garmin_reference

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is known. The description adds meaningful context about what the output contains (formula, inputs, thresholds, caveats), which goes beyond the annotations and helps the agent understand what to expect.

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 two sentences long and front-loaded with the core purpose. It avoids redundancy and every phrase adds value, making it highly concise and well-structured.

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 reference tool with an output schema and two optional parameters, the description provides sufficient context: what it computes, trustworthiness, and usage modes. It could be more explicit about how it relates to sibling tools like garmin_brief or garmin_fitness, but it is otherwise complete.

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 50% (only 'metric' has a description). The description partially compensates by indicating that 'metric' specifies a single metric for in-depth info and that no arguments are needed for the index. However, the 'topic' parameter is not explained, leaving some ambiguity.

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 explains that the tool provides reference information about how metrics are computed, including formulas, inputs, thresholds, and caveats. It is distinct from sibling tools which likely focus on data retrieval or summaries, though it lacks an explicit verb like 'returns' or 'provides'.

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 direct usage guidance: 'No arguments for the index; metric="acwr" for one in depth.' This clarifies two modes of invocation. However, it does not explicitly compare with alternative sibling tools or state when not to use it.

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