Communication and Presentations skill 02 of 13
Slide Design SKILL.md
The Slide Design skill makes Claude, Codex or another AI agent turn a storyline into clear slides. Each slide gets one message, a full-sentence assertion headline and one piece of visual evidence instead of bullets. Charts are redesigned to highlight their point, layouts follow a grid, type and colour are readable and accessible, detail moves to speaker notes and an appendix and pre-read decks get extra explanation.
slide-design/SKILL.md, version 1.0.0, 1,868 words.
Slides fail when they are documents projected on a wall: bullet lists, tiny charts with every data label, three messages per slide and a topic word as the title. The audience reads instead of listening, and the presenter competes with their own slides. Research by Michael Alley and colleagues on the assertion-evidence approach (a full-sentence headline stating the message, supported by visual evidence rather than bullets) found better audience comprehension than traditional topic-and-bullets slides. [Research, Alley et al., assertion-evidence slides] Richard Mayer's multimedia learning principles point the same way: people learn better from words and relevant pictures together, without extra decoration, and when on-screen text does not duplicate everything the speaker says. [Research, Mayer, Multimedia Learning]
This skill turns a storyline into clear slides: one message per slide, an assertion headline, visual evidence (charts, diagrams, images, numbers), simple layouts, readable type, consistent colour, accessible design, charts redesigned to make their point, speaker notes and an appendix for detail. It works in PowerPoint, Google Slides, Keynote or HTML decks.
Operating principles
- One slide, one message. If a slide needs two headlines, it is two slides.
- Assertion headline. A full sentence (up to two lines) that states what the audience should take away.
- Evidence, not bullets. A chart, diagram, image or key number supports the headline.
- Less on screen. The presenter speaks the detail; the slide shows what words cannot.
- Design for the back row and for accessibility. Large type, strong contrast, no colour-only meaning.
- Consistency. One grid, one font family, a small colour palette used with purpose.
Slide anatomy
Headline (assertion): Paid social leads now cost half as much as search leads
Evidence: one chart comparing cost per qualified lead over 6 months, the gap highlighted
Annotation: a short label on the chart: "-48% since June"
Source line: Source: CRM and ad platforms, Apr to Sep 2026
Speaker notes: what to say, the one number to stress, likely questionVisual evidence types
| Message | Best evidence |
|---|---|
| Change over time | Line chart with the key change annotated |
| Comparison | Sorted bar chart, the focus bar in the accent colour |
| Part of a whole | Single stacked bar or a simple table; avoid pie charts with many slices |
| Process or sequence | Simple flow diagram, 3 to 6 steps |
| Structure or relationships | Diagram with boxes and labelled arrows |
| A single striking fact | One big number with a short label |
| A customer or product | Photo or screenshot with a call-out |
| Options or trade-offs | Compact comparison table with the recommendation marked |
When to use, and when not to
Use it after the storyline is clear: to design a new deck, redesign an existing one, fix a slide, simplify charts or prepare a template.
Don't use it to decide what the presentation says (presentation-storyline) or for printed reports (the Workplace Writing reports skill).
Inputs
- The storyline or slide outline with action titles.
- Data and sources for charts.
- The company template, fonts and colours.
- How the deck will be used: presented live, on a video call, sent as a pre-read, or printed.
- Room and screen details if known.
Raw SKILL.md file
This is the exact file agents read, including the credit header and licence notice. Save it as slide-design/SKILL.md.
---
name: slide-design
description: "Design clear slides from a storyline: one message per slide, assertion headlines backed by research, visual evidence instead of bullets, chart makeovers that highlight the point, grids, typography and purposeful colour, accessibility, speaker notes, appendices, templates and pre-read adjustments for PowerPoint, Google Slides, Keynote or HTML. Use whenever someone needs to design or redesign slides, fix a cluttered deck, improve charts in a presentation, build a slide template, make slides readable on video calls or turn bullet slides into visual ones."
license: CC-BY-4.0
metadata:
author: Afeez Adebayo
author_url: https://afeezadebayo.com
author_linkedin: https://www.linkedin.com/in/afeez-adebayo/
author_x: https://x.com/za_icon
source: https://afeezadebayo.com/skills-md/productivity/communication-presentations/slide-design/
category: productivity
subcategory: communication-presentations
version: "1.0.0"
created: "2026-10-10"
updated: "2026-10-13"
---
# Slide Design
Slides fail when they are documents projected on a wall: bullet lists, tiny charts with every data label, three messages per slide and a topic word as the title. The audience reads instead of listening, and the presenter competes with their own slides. Research by Michael Alley and colleagues on the assertion-evidence approach (a full-sentence headline stating the message, supported by visual evidence rather than bullets) found better audience comprehension than traditional topic-and-bullets slides. [Research, Alley et al., assertion-evidence slides] Richard Mayer's multimedia learning principles point the same way: people learn better from words and relevant pictures together, without extra decoration, and when on-screen text does not duplicate everything the speaker says. [Research, Mayer, Multimedia Learning]
This skill turns a storyline into clear slides: one message per slide, an assertion headline, visual evidence (charts, diagrams, images, numbers), simple layouts, readable type, consistent colour, accessible design, charts redesigned to make their point, speaker notes and an appendix for detail. It works in PowerPoint, Google Slides, Keynote or HTML decks.
## Operating principles
1. **One slide, one message.** If a slide needs two headlines, it is two slides.
2. **Assertion headline.** A full sentence (up to two lines) that states what the audience should take away.
3. **Evidence, not bullets.** A chart, diagram, image or key number supports the headline.
4. **Less on screen.** The presenter speaks the detail; the slide shows what words cannot.
5. **Design for the back row and for accessibility.** Large type, strong contrast, no colour-only meaning.
6. **Consistency.** One grid, one font family, a small colour palette used with purpose.
## Slide anatomy
```
Headline (assertion): Paid social leads now cost half as much as search leads
Evidence: one chart comparing cost per qualified lead over 6 months, the gap highlighted
Annotation: a short label on the chart: "-48% since June"
Source line: Source: CRM and ad platforms, Apr to Sep 2026
Speaker notes: what to say, the one number to stress, likely question
```
## Visual evidence types
| Message | Best evidence |
|---|---|
| Change over time | Line chart with the key change annotated |
| Comparison | Sorted bar chart, the focus bar in the accent colour |
| Part of a whole | Single stacked bar or a simple table; avoid pie charts with many slices |
| Process or sequence | Simple flow diagram, 3 to 6 steps |
| Structure or relationships | Diagram with boxes and labelled arrows |
| A single striking fact | One big number with a short label |
| A customer or product | Photo or screenshot with a call-out |
| Options or trade-offs | Compact comparison table with the recommendation marked |
## When to use, and when not to
Use it after the storyline is clear: to design a new deck, redesign an existing one, fix a slide, simplify charts or prepare a template.
Don't use it to decide what the presentation says (`presentation-storyline`) or for printed reports (the Workplace Writing `reports` skill).
## Inputs
- The storyline or slide outline with action titles.
- Data and sources for charts.
- The company template, fonts and colours.
- How the deck will be used: presented live, on a video call, sent as a pre-read, or printed.
- Room and screen details if known.
## Workflow
### Step 1. Confirm one message per slide
Take each slide's action title; split any slide with two messages.
### Step 2. Write the assertion headlines
Full sentences, ideally under 15 words, never more than two lines.
### Step 3. Choose the evidence
For each headline, pick the single visual that proves it (table above).
### Step 4. Simplify charts
Remove gridlines, borders, 3D effects, legends that can become direct labels and data labels that are not needed. Highlight the data point that proves the headline in the accent colour; grey out the rest.
### Step 5. Lay out on a grid
Consistent margins, alignment and positions for headlines, evidence and source lines across slides.
### Step 6. Set typography
One or two font families; headlines around 28 to 36 pt, body at least 18 to 24 pt for live presentations; avoid all caps for long text.
### Step 7. Apply colour with purpose
Neutral base, one accent colour for emphasis, one colour for negative values if needed; check contrast.
### Step 8. Write speaker notes
What to say, the key number, the transition to the next slide and any likely question.
### Step 9. Move detail to an appendix
Backup charts, methodology and full tables go after the closing slide, ready for questions.
### Step 10. Review on the real screen
Check from the back of the room or in a shrunk video-call window; anything unreadable gets bigger or cut.
## Chart makeover checklist
- Headline states the insight, not the metric.
- The key data point is highlighted; everything else is muted.
- Axes start at zero for bar charts.
- Labels sit directly on lines or bars instead of in a legend.
- Units and time period are clear.
- Source is shown in small text.
- No 3D, shadows or decorative backgrounds.
- Numbers are rounded to what matters.
## Text rules
| Do | Don't |
|---|---|
| One sentence headline with the message | One-word topic titles |
| A few words of annotation on visuals | Paragraphs of text |
| Maximum about 6 short lines if text is unavoidable | Nested bullet lists |
| Build complex slides step by step | Reveal everything at once on dense slides |
| Put detail in speaker notes or appendix | Read the slide aloud |
## Accessibility
- Contrast ratio of at least 4.5:1 for text against background (a common accessibility guideline).
- Never rely on colour alone; add labels, patterns or icons.
- Use real slide titles so screen readers and navigation work.
- Add alt text to charts and images in decks that are shared.
- Avoid flashing animations; keep transitions simple.
- Check readability for colour-blind viewers (avoid red and green as the only contrast).
## Templates and design systems
A good team template includes title, section, headline-plus-chart, big number, comparison table, diagram, quote, image and closing slides, with fixed positions, fonts and colours. Templates prevent each presenter from reinventing layouts and keep decks consistent.
## Pre-read deck adjustments
When a deck is sent to be read without a presenter, keep assertion headlines, add a short explanatory sentence under each visual, include an executive summary slide at the start and make sure each slide stands alone.
## Headline rewrites
| Topic title | Assertion headline |
|---|---|
| Q3 revenue | Revenue grew 12% in Q3, driven by renewals rather than new customers |
| Customer feedback | Customers praise support speed but struggle with setup |
| Hiring | We have filled 8 of 12 roles; engineering is the bottleneck |
| Roadmap | Two features ship in November; reporting moves to Q1 |
## Layout patterns
| Pattern | Use |
|---|---|
| Headline + full-width chart | Most data slides |
| Headline + big number + one line | A single striking fact |
| Headline + two-column comparison | Before and after, option A and B |
| Headline + diagram | Processes, structures, systems |
| Headline + image + call-out | Products, customers, places |
| Section divider | Signposting in talks over 15 minutes |
Limiting a deck to five or six patterns keeps it consistent and quick to build.
## Using AI tools for slides
AI tools can draft assertion headlines from a storyline, suggest the best chart type, write chart annotations, produce speaker notes and check every slide for one message and readable text. Generated images and charts still need checking: numbers against the source, labels for accuracy and visuals for brand fit. Never let a tool add data that is not in the source.
## Edge cases and judgement calls
| Situation | What to do |
|---|---|
| Company template is cluttered | Use its simplest layouts; keep headlines and evidence clean |
| Stakeholders want every number on screen | Show the key number; put the rest in the appendix or a handout |
| Very technical audience | More detailed charts are fine, but still one message per slide |
| Video call presentations | Larger text, fewer elements, share the deck link afterwards |
| Conference stage | Big visuals, very little text, high contrast for projectors |
| No designer available | Grid, one font, one accent colour and white space go a long way |
## Handoffs to related skills
- Storyline and action titles: `presentation-storyline`
- Data charts and insights: `data-storytelling`
- Rehearsal and delivery: `presenting-delivery`
- Pitch decks: `pitch-presentations`
- Brand visuals: the Marketing brand and creative skills
## Worked example
A quarterly review deck had 24 slides of bullets with titles such as "Sales" and "Marketing". The redesign wrote assertion headlines ("Mid-market deals closed 30% faster after the pricing change"), replaced bullets with one chart or number per slide, greyed out every bar except the one that proved each headline, raised body text to 24 pt, moved nine detailed tables to an appendix and added speaker notes. The deck went from 24 to 14 slides. Attendees said they could follow the argument without reading, and the discussion focused on the two decisions rather than on finding numbers.
## Common mistakes
- Topic titles instead of message headlines.
- Bullet lists as the default layout.
- Charts with no highlighted point.
- Text too small for the room or call.
- Decoration instead of evidence.
## Output format
```
1. Slide-by-slide plan: headline, evidence type, layout, notes
2. Chart makeover instructions or redesigned charts
3. Typography and colour settings
4. Appendix list
5. Accessibility check
```
## Self-check before you answer
- Does every slide have one assertion headline?
- Is each headline supported by visual evidence rather than bullets?
- Are text sizes and contrast readable from the back and on a call?
- Is detail moved to notes or the appendix?
---
Created by Afeez Adebayo, Marketing, SEO & Growth Expert
Website: https://afeezadebayo.com
LinkedIn: https://www.linkedin.com/in/afeez-adebayo/
X: https://x.com/za_icon
Source: https://afeezadebayo.com/skills-md/productivity/communication-presentations/slide-design/
Licence: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). You may copy, share and adapt this skill, including for commercial use, as long as you credit Afeez Adebayo and link to the source URL above. Keep this notice in any copy or adapted version.
Workflow
Step 1. Confirm one message per slide
Take each slide's action title; split any slide with two messages.
Step 2. Write the assertion headlines
Full sentences, ideally under 15 words, never more than two lines.
Step 3. Choose the evidence
For each headline, pick the single visual that proves it (table above).
Step 4. Simplify charts
Remove gridlines, borders, 3D effects, legends that can become direct labels and data labels that are not needed. Highlight the data point that proves the headline in the accent colour; grey out the rest.
Step 5. Lay out on a grid
Consistent margins, alignment and positions for headlines, evidence and source lines across slides.
Step 6. Set typography
One or two font families; headlines around 28 to 36 pt, body at least 18 to 24 pt for live presentations; avoid all caps for long text.
Step 7. Apply colour with purpose
Neutral base, one accent colour for emphasis, one colour for negative values if needed; check contrast.
Step 8. Write speaker notes
What to say, the key number, the transition to the next slide and any likely question.
Step 9. Move detail to an appendix
Backup charts, methodology and full tables go after the closing slide, ready for questions.
Step 10. Review on the real screen
Check from the back of the room or in a shrunk video-call window; anything unreadable gets bigger or cut.
Chart makeover checklist
- Headline states the insight, not the metric.
- The key data point is highlighted; everything else is muted.
- Axes start at zero for bar charts.
- Labels sit directly on lines or bars instead of in a legend.
- Units and time period are clear.
- Source is shown in small text.
- No 3D, shadows or decorative backgrounds.
- Numbers are rounded to what matters.
Text rules
| Do | Don't |
|---|---|
| One sentence headline with the message | One-word topic titles |
| A few words of annotation on visuals | Paragraphs of text |
| Maximum about 6 short lines if text is unavoidable | Nested bullet lists |
| Build complex slides step by step | Reveal everything at once on dense slides |
| Put detail in speaker notes or appendix | Read the slide aloud |
Accessibility
- Contrast ratio of at least 4.5:1 for text against background (a common accessibility guideline).
- Never rely on colour alone; add labels, patterns or icons.
- Use real slide titles so screen readers and navigation work.
- Add alt text to charts and images in decks that are shared.
- Avoid flashing animations; keep transitions simple.
- Check readability for colour-blind viewers (avoid red and green as the only contrast).
Templates and design systems
A good team template includes title, section, headline-plus-chart, big number, comparison table, diagram, quote, image and closing slides, with fixed positions, fonts and colours. Templates prevent each presenter from reinventing layouts and keep decks consistent.
Pre-read deck adjustments
When a deck is sent to be read without a presenter, keep assertion headlines, add a short explanatory sentence under each visual, include an executive summary slide at the start and make sure each slide stands alone.
Headline rewrites
| Topic title | Assertion headline |
|---|---|
| Q3 revenue | Revenue grew 12% in Q3, driven by renewals rather than new customers |
| Customer feedback | Customers praise support speed but struggle with setup |
| Hiring | We have filled 8 of 12 roles; engineering is the bottleneck |
| Roadmap | Two features ship in November; reporting moves to Q1 |
Layout patterns
| Pattern | Use |
|---|---|
| Headline + full-width chart | Most data slides |
| Headline + big number + one line | A single striking fact |
| Headline + two-column comparison | Before and after, option A and B |
| Headline + diagram | Processes, structures, systems |
| Headline + image + call-out | Products, customers, places |
| Section divider | Signposting in talks over 15 minutes |
Limiting a deck to five or six patterns keeps it consistent and quick to build.
Using AI tools for slides
AI tools can draft assertion headlines from a storyline, suggest the best chart type, write chart annotations, produce speaker notes and check every slide for one message and readable text. Generated images and charts still need checking: numbers against the source, labels for accuracy and visuals for brand fit. Never let a tool add data that is not in the source.
Edge cases and judgement calls
| Situation | What to do |
|---|---|
| Company template is cluttered | Use its simplest layouts; keep headlines and evidence clean |
| Stakeholders want every number on screen | Show the key number; put the rest in the appendix or a handout |
| Very technical audience | More detailed charts are fine, but still one message per slide |
| Video call presentations | Larger text, fewer elements, share the deck link afterwards |
| Conference stage | Big visuals, very little text, high contrast for projectors |
| No designer available | Grid, one font, one accent colour and white space go a long way |
Handoffs to related skills
- Storyline and action titles:
presentation-storyline - Data charts and insights:
data-storytelling - Rehearsal and delivery:
presenting-delivery - Pitch decks:
pitch-presentations - Brand visuals: the Marketing brand and creative skills
Worked example
A quarterly review deck had 24 slides of bullets with titles such as "Sales" and "Marketing". The redesign wrote assertion headlines ("Mid-market deals closed 30% faster after the pricing change"), replaced bullets with one chart or number per slide, greyed out every bar except the one that proved each headline, raised body text to 24 pt, moved nine detailed tables to an appendix and added speaker notes. The deck went from 24 to 14 slides. Attendees said they could follow the argument without reading, and the discussion focused on the two decisions rather than on finding numbers.
Common mistakes
- Topic titles instead of message headlines.
- Bullet lists as the default layout.
- Charts with no highlighted point.
- Text too small for the room or call.
- Decoration instead of evidence.
Output format
1. Slide-by-slide plan: headline, evidence type, layout, notes
2. Chart makeover instructions or redesigned charts
3. Typography and colour settings
4. Appendix list
5. Accessibility checkSelf-check before you answer
- Does every slide have one assertion headline?
- Is each headline supported by visual evidence rather than bullets?
- Are text sizes and contrast readable from the back and on a call?
- Is detail moved to notes or the appendix?
On this page
- When to use this skill, and when not to
- Example prompts
- Example output
- What the agent needs from you
- How this skill hands off to related skills
- How to run Slide Design step by step
- Situations this skill handles
- What makes this skill different
- Practical tips from real projects
- Frequently asked questions
- Changelog
When to use this skill, and when not to
Use it to design a new deck, redesign a cluttered one, fix charts, build a team template or make slides readable on video calls.
Slides fail when they are documents on a wall: bullets, tiny charts and topic titles. Research on the assertion-evidence approach found better comprehension with sentence headlines and visual evidence than with topic-and-bullet slides.
Don’t use it to decide what the presentation says; use Presentation Storyline.
Example prompts
- “Redesign this bullet-heavy deck.”
- “Make this chart prove its point.”
- “Rewrite my slide titles as assertion headlines.”
- “Build a simple slide template for our team.”
- “Make these slides readable on a video call.”
Example output
The skill returns a fixed structure. A shortened example for an imaginary site:
Before: 24 bullet slides with topic titles After: 14 slides, each with an assertion headline and one chart or number Charts: key bar highlighted, others grey; direct labels; sources shown Type: headlines 32 pt, body 24 pt Appendix: 9 detailed tables Speaker notes: added for every slide
Every slide carries one message in its headline and one visual that proves it; everything else moves to notes or the appendix.
What the agent needs from you
The skill asks for the storyline or outline with action titles, data and sources for charts, the company template, fonts and colours, how the deck will be used and room or screen details if known.
How this skill hands off to related skills
Slide Design connects to Presentation Storyline and Presenting and Delivery, plus planned skills for data storytelling and pitch presentations in the Communication and Presentations skills.
How to run Slide Design step by step
- Install the skill as
slide-design/SKILL.md. - Share the storyline and data.
- Write assertion headlines.
- Choose one visual per slide.
- Apply grid, type and colour.
- Check on the real screen.
Situations this skill handles
Slide Design handles these situations:
| Situation | What the skill does |
|---|---|
| Cluttered template | Simplest layouts used |
| Every number wanted | Appendix or handout |
| Technical audience | Detailed charts, one message |
| Video calls | Larger text, fewer elements |
| Conference stage | Big visuals, high contrast |
| No designer | Grid, one font, one accent |
What makes this skill different
Most slide advice is about style. This skill is built on how audiences understand slides: one message stated in the headline, one visual proving it and nothing competing with the speaker.
Practical tips from real projects
- One slide, one message.
- Assertion headline.
- Evidence, not bullets.
- Design for the back row.
A worked example: a quarterly review deck had 24 slides of bullets with titles such as sales and marketing. The redesign wrote assertion headlines such as mid-market deals closed 30% faster after the pricing change, replaced bullets with one chart or number per slide, greyed out every bar except the one proving each headline, raised body text to 24 point, moved nine tables to an appendix and added speaker notes. The deck went from 24 to 14 slides and discussion focused on the two decisions.
Evidence follows the message: line charts for change over time, sorted bar charts for comparisons, single stacked bars or tables for parts of a whole, flow diagrams for processes, boxes and arrows for structures, a big number for a striking fact, images with call-outs for products and customers and compact tables for options.
The workflow confirms one message per slide, writes headlines under about 15 words, chooses evidence, simplifies charts by removing gridlines, borders, 3D effects and unnecessary labels, lays slides out on a consistent grid, sets one or two font families, applies a neutral base with one accent colour and checks contrast, writes speaker notes and moves detail to the appendix. Topic titles become assertions: hiring becomes we have filled 8 of 12 roles and engineering is the bottleneck.
The chart checklist confirms the headline states the insight, the key point is highlighted, bar charts start at zero, labels sit on the data, units and periods are clear, sources are shown and numbers are rounded to what matters. Accessibility means contrast of at least 4.5 to 1 for text, never relying on colour alone, real slide titles, alt text in shared decks, no flashing animations and avoiding red and green as the only contrast. A team template with five or six layout patterns, from headline-plus-chart to big number, comparison, diagram, image and section divider, keeps decks consistent. AI tools can draft headlines, suggest chart types and write notes, but numbers and labels are checked against the source.
Edge cases are common in real organisations. When a company template is cluttered, the skill uses its simplest layouts and keeps headlines and evidence clean. When stakeholders want every number on screen, the key number stays on the slide and the rest goes to the appendix or a handout. Technical audiences can see more detailed charts, but still one message per slide. Video calls need larger text, fewer elements and a shared link afterwards, conference stages need big visuals with very little text and high contrast for projectors, and teams without a designer get a long way with a grid, one font, one accent colour and white space.
Common mistakes are topic titles instead of message headlines, bullet lists as the default, charts with no highlighted point, text too small for the room or call and decoration instead of evidence. The final check confirms each slide has one assertion headline supported by visual evidence, text and contrast are readable from the back and on a call and detail sits in notes or the appendix. The output is a slide-by-slide plan with headline, evidence, layout and notes, chart instructions, typography and colour settings, an appendix list and an accessibility check.
Frequently asked questions
What is an assertion-evidence slide?
A slide with a full-sentence headline stating the message and visual evidence, such as a chart or diagram, instead of bullets.
How much text should a slide have?
A headline and a few words of annotation; detail belongs in speaker notes or an appendix.
What font size should slides use?
For live presentations, headlines around 28 to 36 point and body text at least 18 to 24 point.
How do I make a chart clearer?
State the insight in the headline, highlight the key data, grey the rest, label directly and remove decoration.
How do I make slides accessible?
Strong contrast, no colour-only meaning, real slide titles and alt text in shared decks.
Are pre-read decks different?
Yes. They need short explanations under visuals and a summary slide because no presenter is there.
Changelog
- 1.0.0, 10 October 2026: first release.
Use, adapt and share this skill under CC BY 4.0: credit Afeez Adebayo and link to this page.
