lookup_models

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

No annotations are provided, so the description must carry the full burden. It discloses that it's a read operation (lists/resolves) and that results are scoped to a brand. However, it does not mention any potential side effects (none expected), rate limits, or what happens if the brand is invalid. The conditional behavior is well described.

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?

Only two sentences, no wasted words. The first sentence immediately states the purpose. The second sentence explains the conditional behavior in a structured way. Every part is essential.

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?

The tool has only 2 parameters with simple behavior. The description covers both modes completely. An output schema exists (per context signals), so return value details are not needed in the description. For its complexity, it is fully complete.

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?

Input schema coverage is 100% (both parameters have descriptions). The description adds value beyond the schema by explaining the interaction between 'brand' and 'name': with no 'name' returns all; with 'name' resolves to single. This clarifies the conditional logic beyond the schema's individual 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?

Description clearly states two specific actions: 'List a brand's models' and 'resolve one model name to its id.' It uses a specific verb ('list' or 'resolve') and a resource ('models') scoped to 'brand.' This distinguishes it from sibling tools like 'list_all_models' (no brand scope) and 'list_models_grouped' (grouped 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?

Description explicitly says 'brand is required' and explains behavior with and without 'name.' It provides clear context for when to use each mode. However, it does not mention when to avoid this tool or suggest alternatives (e.g., use 'list_all_models' if you need models across all brands).

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