Find best efforts in an activity

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the description is not burdened with repeating those. It adds that the tool 'returns when each effort happened,' giving useful output context beyond the schema. No contradictions with annotations.

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?

Two sentences, each earning its place: the first defines the tool's purpose with concrete examples, the second gives the alternative tool and clarifies the output. No fluff, front-loaded with the primary use case.

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 tool with 5 parameters, a conditional metric/dimension relationship, and an existing output schema, the description covers the main use, gives examples, and routes to the alternative. Minor gap: it doesn't explicitly state that distance_m and duration_s are mutually exclusive based on metric, but the schema's enum and parameter descriptions already hint at this. The overall guidance is complete enough for correct invocation.

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?

Schema coverage is 100% – every parameter has a description in the schema. The description's examples (e.g., best 1 km, best 5 min) illustrate usage but do not add new semantic meaning beyond what the schema already provides. Baseline of 3 is appropriate since the schema handles parameter documentation.

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 finds best efforts within a single activity, gives concrete examples (fastest pace over a distance like best 1 km, highest average HR/power over a duration like best 5 min), and explicitly names the sibling get_athlete_curves as the alternative for cross-activity bests. This distinguishes it from other activity-related tools with a specific verb and resource.

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?

It explicitly says 'For all-time or period bests across activities use get_athlete_curves,' providing a direct when-not-to-use condition and pointing to the correct sibling. It also implies the tool is for within-activity analysis, leaving no ambiguity about scope.

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