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agent-host-chat-contributions

Build and review cross-cutting agent-host chat behavior through lifecycle contributions. Use when adding turn lifecycle side effects, prompt or context injection, restored-history transformation, protocol-action observation, or when reviewing changes that add code to AgentSideEffects or AgentService.

70

Quality

88%

Does it follow best practices?

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SecuritybySnyk

Passed

No findings from the security scan

The canonical home for this skill is agent-host-chat-contributions in microsoft/vscode

SKILL.md
Quality
Evals
Security

Quality

Content

82%Weight 40%Scale 1-5

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

This is a high-quality, dense rule-set skill: it gives concrete code, exact file paths, a real decision procedure, and hard-won failure-mode guidance, all of it project-specific knowledge Claude could not infer. The main improvements are trimming historical backstory in the hook-history and service-DI sections and possibly moving the ordering catalog and memento details into a reference file.

Suggestions

Tighten the historical justifications (hook reduction from six to four, host-bridge growth from seven to two, the async-gate experiment) to one line each — the rule and the fact it was learned the hard way can survive without the full narrative.

Consider moving the ordering catalog (the per-contribution order values) and the memento lifecycle details into a one-level-deep reference file, keeping SKILL.md to the rule, the decision test, and the hooks table.

Consolidate the implementation workflow (read files → decision test → anatomy checklist → registration → tests) into a single short end-to-end sequence so the checkpoints are visible in one pass.

DimensionReasoningScore

Conciseness

Nearly every section delivers project-specific, non-inferable knowledge (hook semantics, ordering values, memento eviction rules, real failure modes like "d.dispose is not a function") with no explanation of concepts Claude already knows. It is 4 rather than 5 because several historical narratives could be tightened — e.g., "The set was once reduced from six to four", "It grew to seven members before being cut back to two", and the async-gate backstory run long for the rule they justify.

4 / 5

Actionability

The content provides a complete, adapted real code example (the ArtifactToolsContribution class with decorator injection and a working hook implementation), a concrete three-question decision test, exact registration call (`contributions.registerContribution(ArtifactToolsContribution)`), a full hooks reference table with concrete example contributions, specific order values, and named test files. This fully matches the 'copy-paste ready code; specific examples cover the common cases' anchor.

5 / 5

Workflow Clarity

The workflow is well sequenced — read the listed files first, apply the numbered decision test, follow the four-item anatomy checklist, register in the single built-in list, and add tests in the named file — with real validation checkpoints (built-in-sequence regression tests, leaving the old agentSideEffects suite unchanged as extraction proof). It falls short of 5 because the sequence is distributed across concern-based sections rather than one end-to-end walkthrough, and a couple of checkpoints are implicit (e.g., duplicate-id rejection is mentioned only in passing).

4 / 5

Progressive Disclosure

The bundle contains no reference files, and the body is organized into clear, well-scoped sections with a navigable hooks table; its pointers are to real codebase files (src/vs/platform/agentHost/...), clearly signaled and each load-bearing for the workflow. It stays at 4 rather than 5 because at ~177 lines some catalog material (the ordering values list, memento lifecycle details) is inlined at a depth that could live in a one-level-deep reference file.

4 / 5

Total

17

/

20

Passed

Description

87%Weight 40%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

A strong description: it states what the skill does, gives an explicit and multi-branch 'Use when' clause covering both authoring and review scenarios, and anchors itself to specific class names that make it highly distinct. The only weakness is mild jargon density in the opening clause and a few missing natural trigger synonyms.

DimensionReasoningScore

Specificity

The description names concrete actions ("Build and review cross-cutting agent-host chat behavior through lifecycle contributions") and enumerates specific capability areas ("turn lifecycle side effects, prompt or context injection, restored-history transformation, protocol-action observation"), matching the 'several specific actions; minor gaps' anchor. It falls short of 5 because the opening clause 'cross-cutting agent-host chat behavior' is somewhat abstract jargon, and it is not a fully comprehensive catalog of what the skill covers.

4 / 5

Completeness

It explicitly answers 'what' ("Build and review cross-cutting agent-host chat behavior through lifecycle contributions") and 'when' with a concrete "Use when..." clause listing five specific trigger conditions plus a review trigger. This matches the top anchor: both what and when clearly and explicitly stated with concrete trigger phrases.

5 / 5

Trigger Term Quality

Triggers like "prompt or context injection", "restored-history transformation", and "changes that add code to AgentSideEffects or AgentService" are exactly the phrases a developer in this codebase would naturally say when needing the skill. It sits at 4 rather than 5 because a few natural variations are missing (e.g., 'chat contribution', 'lifecycle hook', 'turn admission') and it leans on class names for the review trigger.

4 / 5

Distinctiveness Conflict Risk

The niche is sharply defined by named classes (AgentSideEffects, AgentService) and a named mechanism (lifecycle contributions), so it is clearly distinguishable from any other skill and unlikely to trigger incorrectly. It clearly matches the 'clear niche with distinct triggers; minimal conflict risk' anchor.

5 / 5

Total

18

/

20

Passed

Validation

100%

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 16 / 16 Passed

Validation for skill structure

No warnings or errors.

Repository

posit-dev/positron

Path

.github/skills/agent-host-chat-contributions/SKILL.md

Reviewed

Table of Contents

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