get_activity_power_zones

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only states what the tool does, not any behavioral traits like read-only nature (obvious for a getter), potential error conditions, or requirements (e.g., activity must have power data). The description lacks any disclosure about edge cases or limitations.

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 lines with no wasted words. It front-loads the purpose and includes a structured Args section. Every word earns its place, and the format is clean and easily parsed.

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 simple getter with one parameter and an output schema (which presumably documents the return structure), the description covers the essential purpose and parameter meaning. However, it lacks behavioral context such as prerequisites (e.g., activity must have power data) or what happens for unsupported activities. Given no annotations, it could be more complete, but it's sufficient for a straightforward read operation.

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 0% description coverage, so the description must explain the parameter. It does so in the 'Args:' section: 'activity_id: Garmin activity ID.' This adds meaning beyond the schema's bare type string, clarifying the expected identifier. While minimal, it adequately compensates for the lack of schema documentation for this single parameter.

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 purpose: 'Time spent in each power zone for a cycling or running-power activity.' This specifies the verb (get) and resource (power zone time) and distinguishes it from many sibling tools by focusing on power zones. However, it does not explicitly differentiate from similar get_activity_* tools (e.g., get_activity_details, get_activity_timeseries), so it's not a 5.

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 no guidance on when to use this tool versus alternatives. It only states the purpose without saying 'use this when you need power zone breakdown' or mentioning any exclusions. There is no reference to alternative tools or conditions, leaving the agent to infer appropriate usage.

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