list_capabilities

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

Given no annotations are provided, the description carries the full burden and explicitly discloses 'Read-only; no side effects.' This adds behavioral transparency beyond the schema. It does not go into further details like pagination or large result sets, but for a simple list operation the disclosure is adequate.

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 compact sentences with key information front-loaded. Every sentence earns its place: purpose, safety, usage context, and alternative tool reference.

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 an output schema present and a straightforward list operation, the description provides sufficient context for the agent to select and invoke the tool. The only notable gap is the undocumented server_version parameter, which slightly reduces completeness.

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 only 50%: model_id is documented in the schema, but server_version has no description and is required. The tool description does not explain server_version at all, missing an opportunity to compensate for the schema gap. Only model_id's purpose is indirectly implied by 'for a model.'

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 states a specific verb ('list') and resource ('capabilities for a model'), clearly defining the tool's purpose. It also differentiates itself from the sibling tool 'get_capability' by noting it enumerates every capability rather than fetching one.

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 states when to use it ('to enumerate a model's capabilities') and provides an alternative ('use get_capability instead' for full detail of a single capability). Also notes read-only nature, giving clear usage context.

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