get_performance_metrics

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

With no annotations, the description carries full responsibility for disclosing behavior. It only says 'available' metrics, which is vague, and does not state whether this is read-only, how the 'day' parameter affects results, or what happens if no data exists. No side effects or limitations are 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 a single concise sentence that is front-loaded with the action and key metric types. It contains no filler words or redundant information, so every word earns its place.

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?

The tool has a simple schema and no output schema, but the description still leaves gaps. It lists what metrics are fetched but not how the optional 'day' parameter modifies results, what 'available' means, or the response structure. Given the sibling tools, a sentence clarifying scope would improve 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?

The schema has one parameter 'day' with no description (coverage 0%), and the tool description does not mention it at all. The name 'day' provides minimal meaning, but its format, allowed values, and effect on the fetched metrics are unexplained.

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 uses a specific verb 'Fetch' and lists concrete metric categories (VO2 max, recovery, race-prediction, training-status), clearly stating what the tool provides. It does not explicitly distinguish from siblings like get_recovery_snapshot, but the scope is well-defined.

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?

No guidance is provided on when to use this tool versus alternatives. The description does not mention any context, prerequisites, or exclusions, leaving the agent to infer usage purely from the tool name and sibling list.

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