List models

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), so the bar is lower. The description adds genuinely useful context beyond them: the catalog is refreshed hourly from a live source, and the schema's refresh flag bypasses that cache, which tells the agent about staleness and cost trade-offs.

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?

Three tight sentences, front-loaded with what is listed, followed by filtering, then downstream usage and cache cadence. No redundant or filler text.

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?

With no output schema, the description must hint at the return shape; it does so by naming the aliases/ids and categories, but does not describe the fields returned per model (e.g. provider, id, alias). Combined with full schema coverage and annotations, it is close to complete but leaves the return shape somewhat implicit.

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 description coverage is 100%, with per-parameter docs covering refresh, category enum, and provider key/name case-insensitivity and combinability, so the schema does the heavy lifting. The description only repeats the provider example ('google') and combinability, adding no new semantics beyond the schema.

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 (list) and resource (model catalog), enumerates the catalog categories, and notes what is returned (short aliases usable as 'model'). This clearly separates it from siblings like list_tasks/list_resources and from the generate_* tools that consume its output.

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 concrete usage context: filter by category and/or provider, and use the returned ids/aliases on the generation tools, which implicitly positions this as the lookup step before generation. It stops short of stating when not to use it (e.g. that it should not be polled frequently because of the cache), so it is clear but not exhaustive.

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