list_models

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

With no annotations, the description carries the full burden. It discloses the OPENROUTER_API_KEY requirement, one-hour result caching, and force_refresh bypass behavior. The word 'browse' implies a read-only operation, though pagination, rate limits, and exact return format are not mentioned.

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 front-loaded with purpose, followed by a compact AUTOMATIC TRIGGERS block, then requirements and a terse parameter list. Every section earns its place, and there is no filler or redundant prose.

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 tool with no annotations and no output schema, the description covers purpose, triggers, prerequisites, caching, and all parameter semantics. It could be more complete by stating the exact return shape or pagination behavior, and by pointing to siblings like get_model_details for single-model details, but it is sufficient for 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?

Schema description coverage is 0%, but the description's PARAMETERS section fully compensates by explaining all six parameters: search scope, provider examples, combined input+output price semantics, minimum context length, free-only filtering, and cache-bypassing force_refresh. This adds meaning well beyond the raw schema.

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 a specific verb and resource: browse available models from the OpenRouter API, with filtering by provider, price, or context size. It does not explicitly differentiate from sibling tools like get_model_details or recommended_models, but the scope is evident and distinct enough for basic selection.

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 gives explicit automatic triggers: call when the user asks what models are available, when choosing a model for a collab session, or when comparing pricing/context limits. It does not mention when not to call or name alternative tools, but the usage context 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.