sharing-learnings

How to record project learnings so that later-phase workers and future agent runs can consume them.

npx skills add https://github.com/microsoft/github-copilot-modernization --skill sharing-learnings

Sharing Learnings

This skill defines how a multi-agent run captures knowledge and feeds it back into later phases and future runs.

ProductPathScopeAudience
Learnings{{BASE_PATH}}/learnings/<role>/<slug>.md (git-tracked)persistent across runslater-phase agents in same run + future agents on this repo + humans

Invoked by every worker during Preflight Step 2 (consume prior learnings) and Completion Phase (produce new learnings).


1. Directory Layout

{{BASE_PATH}}/
└── learnings/<role>/<slug>.md   ← per-topic, append-friendly, git-tracked

The directory tree + filename is the index. Each file's first three lines (H1 + blank + one-sentence description) are its scannable metadata. No separate index file needed.


2. Consuming Learnings (Preflight Step 2)

  1. list_dir {{BASE_PATH}}/learnings/<your-role>/ (and any cross-cutting roles relevant to your task).
  2. Read only the first 3 lines of each file (H1 + blank + one-sentence description). Decide relevance from that sentence alone.
  3. read_file the full body only for learnings that are relevant to your current task.

Emit once after loading:

[learnings-loaded] <role>/<slug>, <role>/<slug>

Use (none) if nothing relevant was found. If a learning conflicts with your task or charter, [notify:coordinator] — do not silently ignore.


3. Learning File Format

Every file under {{BASE_PATH}}/learnings/ MUST follow this shape:

# <Slug Title>

One-sentence description that future agents scan to decide relevance.

## What Happened
Narrative: what was discovered, what went wrong, what worked.
Cite the originating project + task ID.

## Takeaway
Concrete guidance for future tasks dealing with the same topic.

## Example (optional)
Minimal snippet illustrating the point.

## History
- <YYYY-MM-DD> (<project>/<taskId>): initial
- <YYYY-MM-DD> (<project>/<taskId>): added X based on new finding

Blank template: templates/learning.md.


4. Producing Learnings (Completion Phase)

Before finishing your task, evaluate what you learned and decided.

When to write

Mandatory — you MUST write a learning when any of these apply:

  • You made a code-style or naming convention choice (e.g. camelCase vs snake_case, tab width, import ordering)
  • You made an architecture or design decision (e.g. injection style, module boundaries, error-handling strategy, API shape)
  • You chose a library, framework version, or configuration that affects project consistency

These learnings ensure style and architecture stay consistent across runs, even if the choice felt obvious.

Optional — write a learning when any of these apply:

  • Something failed or surprised you, and the resolution is worth recording
  • A pattern emerged across multiple files/decisions in the task
  • A framework/library/tool behaved differently than expected
  • A source→target mapping rule would apply to other modules too

Doing nothing is valid only if the task involved no style/architecture decisions and had no surprises.

How to write

  • One topic per file. The slug should make the topic clear (kebab-case, e.g. war-packaging-for-jsp.md).
  • Role ownership. Write under {{BASE_PATH}}/learnings/<your-own-role>/. If you spot something that belongs to another role, use [notify:<that-role>] instead.
  • Append to existing files. If a file with a matching slug already exists and covers the same topic, append a new ## History entry rather than creating a duplicate. Add new details under the existing sections.
  • Keep it short. Target < 40 lines. If it's longer, split into separate files.

Emit after writing (empty list is fine):

[learnings] written: [<role>/<slug>, ...]