get_activity_splits

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

Annotations are not provided, so the description carries the full burden. It correctly indicates this is a read operation (retrieves data) and specifies the return structure (per distance unit splits with pace and heart rate changes). However, it doesn't disclose whether splits are calculated automatically, what happens if the activity lacks GPS data, or if there are rate limits. A score of 3 reflects basic transparency without deeper behavioral insight.

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 concise, with one introductory sentence and a single parameter definition. Every sentence is necessary and adds value. No filler or redundancy. There is no structural issue.

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's simplicity (single parameter, clear output schema implied by the description, no nested objects), the description is nearly complete. It covers the tool's purpose, parameter semantics, and basic output. The only minor gap is not specifying what happens if the activity_id does not exist or if splits are unavailable, but with an output schema present, return values need not be fully explained.

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 description coverage is 0%, so the description must compensate. It provides a clear, human-readable definition for the single parameter 'activity_id' as 'The numeric id of the activity.' This adds meaning beyond the schema, which only states type and title. With only one parameter, this is sufficient, earning a 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 explicitly states it returns 'per-kilometre or per-mile splits for one activity, showing how pace and heart rate changed through the effort,' clearly specifying the verb (get), resource (splits), and scope (one activity, per distance unit). This distinguishes it from siblings like get_activity_details, which would provide overall activity summary, and get_heart_rate, which is broader.

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 does not provide explicit guidance on when to use this tool versus alternatives like get_activity_details or list_activities. Usage is implied by the semantics of the tool name and description (i.e., to examine splits), but no exclusions or prerequisites are given. A score of 3 is appropriate as it is minimally adequate but lacks clear context.

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