get_available_models

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

No annotations are provided, so the description bears the full burden. It discloses the operation (list) and the return type ('Dictionary with model registry'), but it does not explicitly state that it is a read-only operation, nor does it mention any side effects, authorization requirements, or rate limits. For a simple retrieval tool, the implied read-only nature is acceptable, but a more explicit statement would be better.

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?

The description is concise: three sentences plus a brief 'Returns:' note. The key purpose is front-loaded, and there is no extraneous information. Every sentence earns its place, making it efficient 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?

For a read-only tool with no parameters and no output schema, the description is complete. It clearly states what the tool does and what it returns. It does not require additional details about authentication or pagination, as these are not indicated by any schema or annotation. The description fully supports correct invocation.

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?

The tool has zero parameters, so the schema covers everything trivially. Per the baseline for 0 parameters, a score of 4 is appropriate. The description does not (and need not) add parameter semantics because there are none.

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 clear purpose: 'Get list of all available models and their capabilities.' It specifies the resource (models) and the action (get list), and distinguishes from sibling tools like list_agents by targeting models rather than agents. The verb and object are unambiguous.

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?

The description explicitly says 'This tool should be called by Claude to discover which models are available and what tasks they're best suited for,' which gives a clear use case. It does not explicitly mention alternatives or when not to use it, but the context of available sibling tools (agents, safety config) makes the intended use clear enough. A bit more directness on exclusions would push to 5.

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