get_athlete_zones

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

Annotations are absent, so the description carries the full burden. It does state the tool 'returns' data, implying a read-only operation, but adds no further context on authentication, rate limits, or error behavior. For a simple no-parameter read, this is minimally adequate but not rich.

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, front-loaded sentence with no wasted words: it names the verb, resource, and the two zone types. It is perfectly sized for a tool with no parameters and a simple purpose.

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 zero-parameter read tool with no output schema, the description states exactly what is returned (heart-rate and power zones). It doesn’t mention units or response structure, but given the simplicity of the call, little more is strictly necessary.

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 tool has zero parameters, and schema coverage is 100% with an empty properties object. There is nothing to document, so the description carries no additional parameter burden – baseline 4 applies.

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 identifies the specific verb 'Return', the resource ('the athlete's configured heart-rate and power zones'), and scopes it to zones, which distinguishes it from siblings like get_athlete and get_activity. Even without seeing the schema, an agent can tell this is the zones-fetching endpoint.

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 call this tool versus alternatives like get_athlete or get_stats. There’s no mention of prerequisites, contextual triggers, or exclusions – the agent must infer that this is for zones specifically.

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