@deepseek-ai/dsh-tool-skill
The model-facing skill catalog and skill tool.
Requires ctx.tools and ctx.skills (inject: ['tools', 'skills']).
Session-prefix catalog
The plugin contributes one user-role <system-reminder> catalog through agent/session-prefix. It resolves skills for the calling session's cwd, forwards the prefix abort signal to discovery, and lists only sorted name and description entries; skill bodies, paths, sources, providers, and whenToUse hints remain outside the catalog. The catalog is omitted when no model-invocable skills are available, and also when that agent's tool view restricts away the shipped skill tool or resolves a same-name scoped shadow instead. This exact-definition check keeps prompt guidance, the model-visible schema, and executable dispatch aligned.
catalogDescriptionMaxLength controls normalized, XML-escaped catalog descriptions. Its default is 500 and values must be integers of at least 3, which reserves room for a truncation ellipsis. The session-prefix RFC defines the request-only, header-logged lifecycle of this message.
Tool: skill
| Arg | Type | Notes |
|---|---|---|
name |
string (required) | Exact kebab-case skill name from the available skills listing. |
Execution uses the calling agent's session.header.cwd so workspace-sensitive providers can resolve the right winning skill. A successful call returns one text tool result with <skill_content name="...">, containing <skill_resources> followed by <skill_instructions>. Resource guidance resolves paths or URLs explicitly referenced by the loaded instructions against resourceBase; referenced scripts, references, and assets load only when needed, and the tool does not enumerate a skill directory. Local filesystem skills provide a base directory, while remote or embedded providers can provide a URL or opaque provider-managed guidance. A name that cannot be resolved reports that the skill is unknown or no longer available; invalid names and skills marked disableModelInvocation: true retain distinct isError results.
The tool does not call agent.inject() in v1. Its result is already recorded as the tool result and becomes available to the next model step without duplicating the content as synthetic context.
Model Experience
| Context surface | What the model sees | Token effect |
|---|---|---|
| Session prefix | If model-invocable skills exist and this exact skill tool is visible, the agent receives one user-role <system-reminder> listing sorted names and capped descriptions. The composed catalog is frozen for the loop instance and prepended to every request, outside ordinary history. |
Repeated input cost scales with skill count and catalogDescriptionMaxLength; no catalog tokens are sent when the list is empty or the tool is hidden or shadowed. |
| Tool schema and result | The model sees the fixed skill(name) schema. A successful call returns the selected full instructions plus resource-resolution guidance; no duplicate agent.inject() copy is made. |
Fixed schema cost per request. Loaded instructions are data-dependent tool-result tokens, resent on later steps until compaction. |
Known Limitations and Deferred Work
- The catalog omits
whenToUse, source, and provider metadata — routing is based only on name and a capped description;whenToUseremains provider metadata and is not rendered by the loaded wrapper either. - Loaded instruction bodies have no size cap — a provider can return a skill large enough to consume substantial next-step context; only catalog descriptions are truncated.
- Resources are guidance, not attachments — the tool reports a base directory/URL/opaque hint but neither enumerates nor fetches referenced files for the model.
- Loading is one-shot text — there is no partial, streaming, or cached-content handle when a remote provider is slow or a skill body is large.