Add output-only rule for example files

skill-authoring-guide.md

@@ -143,7 +143,9 @@ Present variations neutrally (A, B, C) without labeling them with descriptors. L
 
 Every skill should include a `references/` directory with a sample output file named `example-[description].md` (e.g., `example-output.md`, `example-positioning-brief.md`). The `references/` directory is part of the [Agent Skills open standard](https://agentskills.io). It may also contain glossaries and other supporting documentation the skill reads at runtime.
 
-Example files use the `example-` prefix so they are distinguishable from other reference documents. The example serves as both a quality benchmark for the LLM and a preview for the user.
+Example files use the `example-` prefix so they are distinguishable from other reference documents. The example serves as both a quality benchmark for the LLM and a preview for the user on the skill page.
+
+The example file should contain only the skill's actual output. Do not include preambles ("This example demonstrates..."), "How to use this document" sections, or commentary explaining what the example shows. The output should speak for itself.
 
 ### Fictional brand naming
 

skills/adapt-skill/SKILL.md

@@ -139,7 +139,7 @@ Output must be ready to paste into a CMS, upload to a platform, or hand to a tea
 
 Every skill includes an example output file in `references/`. The file must use the `example-` prefix (e.g., `example-output.md`). The SkillShelf website uses this prefix to find and display example files. A file named `sample-output.md` or `output-example.md` will not appear on the site.
 
-The example demonstrates the ceiling, not the floor. If the example is mediocre, the LLM will calibrate to mediocre output.
+The example demonstrates the ceiling, not the floor. If the example is mediocre, the LLM will calibrate to mediocre output. The example file should contain only the skill's actual output, with no preambles, commentary, or "how to use" sections.
 
 ### General behaviors
 

skills/adapt-skill/references/conventions-checklist.md

@@ -60,6 +60,7 @@ Use this checklist during Phase 4 to review a skill against SkillShelf standards
 - [ ] Brand name makes product category immediately clear
 - [ ] Example demonstrates ceiling quality (not floor)
 - [ ] Example covers all output sections
+- [ ] Example contains only the output (no preambles, commentary, or "how to use" sections)
 
 ## Ecosystem
 

skills/write-skill/SKILL.md

@@ -176,7 +176,7 @@ Output must be ready to paste into a CMS, upload to a platform, or hand to a tea
 
 Every skill includes an example output file in `references/`. The file must use the `example-` prefix (e.g., `example-output.md`). The SkillShelf website uses this prefix to find and display example files. A file named `sample-output.md` or `output-example.md` will not appear on the site.
 
-The example demonstrates the ceiling, not the floor. If the example is mediocre, the LLM will calibrate to mediocre output.
+The example demonstrates the ceiling, not the floor. If the example is mediocre, the LLM will calibrate to mediocre output. The example file should contain only the skill's actual output, with no preambles, commentary, or "how to use" sections.
 
 ### General behaviors
 

skills/write-skill/references/conventions-checklist.md

@@ -60,6 +60,7 @@ Use this checklist during Phase 4 to review a skill against SkillShelf standards
 - [ ] Brand name makes product category immediately clear
 - [ ] Example demonstrates ceiling quality (not floor)
 - [ ] Example covers all output sections
+- [ ] Example contains only the output (no preambles, commentary, or "how to use" sections)
 
 ## Ecosystem