Get pattern by id

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the behavioral burden. 'Fetch' implies a read operation and the description states what is included in the result. However, it does not disclose error behavior for missing ids, return shape structure, or whether composed components are full objects or references. The description adds some context but not comprehensive detail.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single focused sentence that front-loads the verb and resource, states the key constraint, and notes what is included in the result. There is no wasted wording or redundant repetition of the title.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple one-parameter getter with no output schema, the description covers the essential facts: what to fetch, by what id, and what the result includes. It is complete enough for an agent to invoke the tool correctly, though a note on not-found behavior would make it fully robust.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema provides no description for the 'id' parameter (0% coverage), so the description must compensate. The phrase 'exact stable registry id' adds semantic meaning beyond the raw schema, indicating the id must be an exact, stable identifier rather than a search term. Still, it does not explain id formatting, examples, or how the id relates to pattern versions.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the action ('Fetch'), the resource ('a single UI pattern'), and the lookup mechanism ('exact stable registry id'). It also adds a meaningful detail about the response ('including the components it composes'). It does not explicitly distinguish itself from sibling tools like registry_get_component or registry_get_token, but the resource type makes the distinction reasonably clear.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The phrase 'by its exact stable registry id' provides clear context: use this tool when you already have the precise, stable id of a pattern. It does not mention alternatives or exclusions, but for a simple get-by-id operation the usage context is adequately implied.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.