tp_get_zone_methods

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 discloses that the tool is read-only ('probes the zone calculator (read-only)') and explains the 'derives_threshold' flag behavior. However, it could briefly mention whether any data is mutated, which is implied as none.

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 three sentences that efficiently convey purpose, technical context, and scope. It is front-loaded with the main action. While informative, it could be slightly more concise, but the added detail is relevant.

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 absence of an output schema, the description fully specifies what the tool returns: zone count, zone labels, and the 'derives_threshold' flag. It also covers scope and the technical reason for the tool. No gaps remain for an agent to invoke it correctly.

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 input schema has 100% coverage for the single parameter 'metric', including a description. The description adds value by explicitly stating 'Omit to list all three,' which goes beyond the schema's 'Limit to one metric.' This extra guidance justifies a score above the baseline of 3.

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 explicitly states 'List available zone-calculation methods per metric (power / heartrate / speed), each with its zone count and zone labels.' This is a specific verb+resource+output combination that clearly distinguishes the tool from its siblings, which are mostly CRUD operations for other entities.

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 explains why this tool exists ('TP has no method-names endpoint and settings store only an opaque method int') and what it does ('fingerprint each method'). It also clarifies scope ('Coach-scoped (uses your own user), not athlete-specific'), guiding the agent on when to use and 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.