get_activity_zones

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

No annotations are provided, so the description carries the full burden. It uses read-only verbs ('Get', 'Shows') implying a safe read operation, but does not disclose any additional behavioral aspects such as return format, pagination, or potential errors. This is adequate for a simple read tool but lacks deeper 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?

The description is extremely concise, two sentences, front-loaded with the main action, and contains no redundant information. 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?

Given the tool has only one parameter, no output schema, and a straightforward read operation, the description is largely complete. It explains what is returned (time per zone) and is well differentiated from siblings. A slight gap is the lack of mention of response structure, but this is not critical for a simple 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?

The schema already fully describes the only parameter (activity_id) with 100% coverage. The description adds minimal extra context by referencing 'a specific activity', which aligns with the schema. The baseline of 3 is appropriate since the schema handles parameter semantics.

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 the tool retrieves heart rate and power zone distribution for a specific activity, using the verb 'Get' and naming the exact resource. It distinguishes itself from sibling tools like get_activity and get_activity_laps by focusing specifically on zone distribution.

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 provides clear context for when to use the tool: when a user needs heart rate and power zone distribution for a specific activity. It does not explicitly mention alternatives or when not to use it, but the context is specific enough for an agent to select it appropriately among siblings.

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