get_stats

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

With no annotations provided, the description must disclose behaviors itself. It states 'Read-only operation' and that only activities with 'Everyone' visibility are included, which are important constraints. However, it does not mention response format, potential empty results, or authentication requirements beyond the schema, so it is thorough but not exhaustive.

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 and structured, with a clear title, endpoint, and key details front-loaded. It avoids fluff and each line serves a purpose, though the title and description overlap slightly.

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 does not explain the structure or content of the returned stats (e.g., distance, time, elevation). It also omits any error scenarios or rate-limit notes. For a simple read-only endpoint this is a moderate gap that could impact an agent's ability to interpret results 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 schema has 100% coverage, and the single parameter 'id' is described as 'Must match the authenticated athlete.' The tool description adds no additional semantic nuance about the parameter. This meets the baseline but offers no extra value.

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 identifies the resource ('activity stats of an athlete') and the specific action (GET). It also notes the visibility filter, which distinguishes it from other stats-related tools like zones or segments. While it doesn't name siblings, the scope is explicit enough for an agent to differentiate.

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 implies usage for retrieving athlete stats but does not explicitly state when to choose this tool over alternatives. The visibility note provides context about data scope but no direct guidance on tool selection among the many sibling getters. This is a clear but not fully specified usage context.

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