llm_model_usage

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

No annotations; description specifies it analyzes and returns statistics, suggesting read-only behavior, but doesn't explicitly state idempotency or side effects. Lists output components, adding some transparency.

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?

Structured with bullet points for easy scanning; concise without excess. Redundancy in repeating default value from schema is minor.

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?

Output schema exists but description only says 'formatted usage statistics and analysis'; missing details on format or pagination. No behavioral context like permissions or latency, but adequate for a statistics tool.

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 has 0% description coverage; description explains the 'hours' parameter as lookback time with default, providing full meaning beyond schema. Single parameter, well-documented.

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?

Clearly states it analyzes model selection in routing and shows usage statistics including top models, task type distribution, etc. Distinct from siblings by focusing on model routing, but doesn't explicitly differentiate.

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?

Indicates it shows statistics for last N hours, implying monitoring use, but lacks explicit when-to-use or alternatives guidance. No exclusions or context for when not to use.

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