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

Annotations already cover the safety profile (readOnlyHint=true, idempotentHint=true, destructiveHint=false), so the description does not need to repeat that. It adds value by enumerating the return contents (mile splits, heart rate, cadence, calories, device), which tells the agent what behavioral payload to expect beyond the schema.

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?

Three short sentences deliver the core content first, then the ID source, then the alternative tool. There is no filler or repetition of annotation/schema details. Every sentence 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?

For a single-parameter read-only tool with a full output schema and rich annotations, the description covers everything an agent needs: what data is returned, where the ID comes from, and when to choose a different tool. It is complete for this complexity level.

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 describes activity_id as 'Run id from ourpr_list_runs,' and the description reinforces the same provenance, which is helpful. Since schema coverage is 100%, the baseline is 3; the description adds a small but meaningful amount by tying the ID to a specific listing tool, nudging it to 4.

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 begins with a specific verb and resource: "One activity in full," and enumerates the precise contents (mile splits, heart rate, cadence, calories, device). It also differentiates itself from the sibling ourpr_run_stream by explicitly pointing there for route profile data, so an agent can distinguish it from other run-related tools.

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 states the source of the required ID ('Id comes from ourpr_list_runs'), telling the agent the prerequisite call. It also provides an explicit alternative: 'For the profile along the route, use ourpr_run_stream.' This is clear when-to-use and when-not-to-use guidance.

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