list_models

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

Discloses important behavioral trait 'without pinging' and explains output fields (model_id, label). No annotations exist, so the description carries the burden. It does not mention side effects, but it's a read operation.

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?

Concise yet comprehensive: one sentence for purpose, one for response structure, and bulleted parameter descriptions. No wasted words.

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?

Given the output schema exists and the description explains output fields, the tool is fully specified for its purpose. Covers what it does, when to use, parameters, and response.

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?

With 0% schema coverage, the description provides detailed explanations for all 4 parameters, including valid values for tier, examples for min_tier, and meaning of free_only. This fully compensates for the lack of schema descriptions.

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 'List models in the catalog' and explicitly says when to use it: 'Use when the user asks what models are available or to browse by tier/provider/free.' It distinguishes itself from siblings by focusing on listing without pinging.

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?

Provides explicit usage context ('Use when...'), but does not mention when not to use it or compare directly to alternatives like get_fastest or scan. Still, the guidance is clear and actionable.

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