search_intervals

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

No annotations are provided, so the description must disclose behavioral traits. It states the search scope ('across all activities') and return type, but fails to explain what 'similar' means (e.g., exact matching vs fuzzy), result ordering, or performance limitations. The ambiguity of 'similar intervals' leaves key behavior undisclosed.

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 well-structured with clear Arg and Returns sections. It is concise but slightly redundant: the first two sentences both state the search intent. Overall, it is appropriately sized and front-loaded with the core purpose.

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 read-only search tool with all-optional parameters and an output schema, the description is fairly complete. It explains the cross-activity scope and gives usage context. However, it does not clarify the meaning of 'similar intervals' or how the search matches criteria, which is a notable gap for a tool that relies on such semantics.

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 input schema already documents all parameters (100% coverage), so the baseline is 3. The description adds value by providing concrete example values for interval_type ('WORK', 'THRESHOLD', 'VO2MAX') and reaffirming the default for limit, which helps an agent understand expected inputs beyond the schema.

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 a specific verb and resource: 'Search for similar intervals across all activities' and 'Finds intervals matching specific criteria across your activity history.' It distinguishes from sibling tools like get_activity_intervals (which retrieves intervals for a single activity) and search_activities (which searches activities, not intervals).

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 provides clear context on when to use the tool: 'Useful for tracking progress on specific workout types or finding comparable training sessions.' It does not explicitly mention exclusions or alternative tools, but the use cases are concrete enough to guide selection.

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