list_models

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

Despite having no annotations, the description transparently discloses that the tool reads model availability and default selections. It doesn't mention potential errors or prerequisites (like needing to set an API key), but for a read-only list operation, the behavioral surface is small and the description covers the essential behavior without contradiction.

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 a single, focused sentence that leads with the action 'List' and immediately specifies the resource and additional details about default selections. No redundant words, and the structure places the core purpose first.

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 parameterless tool with an output schema present, the description is fully sufficient. It states exactly what the tool returns: available models and default choices. The provided output schema likely explains the return structure, so no further exposition is needed. The sibling tools don't introduce ambiguity that would require more context.

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?

This tool has zero parameters, so the description doesn't need to explain parameter syntax or meaning. The input schema confirms this, and the guideline for 0 params sets baseline 4. The description adds nothing about parameters because none exist, which is appropriate.

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 the tool lists models available on the API key and notes the server's default picks for generation and vision. It uses a specific verb 'List' and the resource 'models', distinguishing it from siblings that set API keys or generate/describe images.

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 implies usage: call this to discover available models and defaults. However, it gives no explicit guidance on when to use it versus alternatives, nor when not to use it. Given its simple listing nature, the context is reasonably clear, so this is barely adequate rather than poor.

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