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

Annotations already declare a safe, closed read (readOnlyHint=true, openWorldHint=false), so the description only needs to add context. It does: it discloses that results include models across three media kinds and that prices shown are starting prices, a pricing caveat not visible in the schema. No mention of result size, pagination, or whether every model in a category is returned.

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?

Two short sentences with zero filler: the first says what is returned, the second gives the workflow instruction. Front-loaded and easy to scan.

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 correctly covers the shape of results (models plus starting prices) and when to invoke it, which is enough for a no-required-parameter list tool. The remaining gap is returning-result expectations such as ordering, completeness, or result volume.

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%, so both filters are already documented, and the enum for type is self-explanatory. The description only indirectly alludes to the type filter through the words 'video, image and music', and adds nothing about how query matching behaves 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 and resource ('List the video, image and music models') plus what each item carries ('the starting price of each'), which clearly separates it from the singular sibling get_model and from estimate_cost.

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?

Explicitly says 'Call this first to pick a model', giving an ordering rule for a model-selection workflow. It does not name the natural follow-up (get_model for full details, estimate_cost before create_generation), so the alternative routing is only implied.

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