get_activity_details

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

No annotations are provided, so the description carries the full burden. It communicates that this is a read-style operation and provides auth context by noting the API key is optional and falls back to API_KEY from .env. However, it does not disclose output shape, error behavior, rate limits, or what 'detailed information' concretely includes.

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 short, front-loaded with the core action, and uses a clean Args block for parameter details. Every sentence earns its place without redundant exposition.

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 fetch-by-ID tool, the description covers the operation, the service source, both parameters, and the auth fallback behavior. The existence of an output schema partially accounts for the lack of return-value documentation. Its main gap is not explaining when this tool should be selected over competing activity-fetching siblings.

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 provides no parameter descriptions, and the context notes 0% schema coverage, so the description must compensate. It does so clearly: activity_id is defined as 'The Intervals.icu activity ID', and api_key is explained as optional with an env fallback. This gives an agent enough semantic grounding to invoke the tool.

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 action ('Get') and the resource ('detailed information for a specific activity from Intervals.icu'), making the tool's basic purpose understandable. However, it does not differentiate it from sibling tools like get_activity_raw, get_activity_intervals, or get_activity_streams, so an agent may still be unsure which activity-related fetch tool to choose.

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?

There is no guidance about when to use this tool versus the many sibling tools that also fetch activity data. The description only defines what the tool does and its parameters; it does not state prerequisites, exclusions, or alternatives. An agent is left to infer usage context.

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