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

With no annotations, the description carries the full burden and mostly does: it discloses the default payload size ('a few KB rather than the whole capability'), the alternate envelope returned by full:true, and the auth path for the token parameter. It never spells out the read-only/no-side-effect nature or pagination behavior, so it stops short of exhaustive.

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?

Front-loaded with the verb, resource and the 'Start here' cue, and every sentence is informative. The middle run describing the slot/property encoding syntax is dense enough to read as a wall of text, but the content is not padding.

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?

An output schema exists, so return values needn't be detailed; the description nonetheless supplies the shape difference between summary and full modes, the precondition for valid catalogPin values, and token usage. Nothing an agent needs to invoke it correctly is missing.

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?

Schema coverage is 100%, so the baseline is 3, but the description adds real meaning beyond the schema: it characterizes what full:true returns (adapter status, parity, export notes per component) and what componentIds narrows from, rather than just restating field names.

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?

States a specific verb and resource with scope ('the component catalogs a UI-builder design can pin to'), which cleanly separates it from the unrelated catalog_* siblings and from ui_builder_search_components. The 'Start here' framing establishes it as the entry point in a workflow rather than a generic list.

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?

Gives a clear context for calling it (a design's catalogPin must name a revision this server serves, so consult this first) and explains when to use full:true versus the default summary, plus when to narrow with componentIds. It stops short of naming explicit exclusions or a sibling to prefer in other cases.

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