polar_get_activities

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

Annotations already establish read-only, idempotent, and non-destructive behavior. The description adds valuable context about the nature of the data ('preprocessed', specific breakdowns), making expectations clear without contradicting the 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?

The description is a single, well-structured sentence that packs all essential information without fluff or redundancy. It reads naturally and efficiently.

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?

Since there is no output schema, the description does a good job of communicating what the response will contain (daily activity summaries, hourly step buckets, zone durations). It could be slightly more specific about response structure or pagination, but overall it gives enough context for an agent to understand the tool's scope.

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 descriptions already cover all parameters (from, to, format) with formats, defaults, and behavior. The tool description adds no significant new semantic information beyond repeating the date-range behavior, so the baseline score of 3 is appropriate.

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's purpose with a specific verb ('Get') and explicitly enumerates the resource (daily activity summaries) and the included data (hourly step buckets, zone duration breakdowns). It distinguishes well from sibling tools like polar_get_exercises or polar_get_heart_rate.

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 indicates when to use it (retrieve activity summaries) and mentions the optional date-range filter, giving useful context. However, it does not explicitly mention when to prefer alternative tools (e.g., for exercise details or sleep data), so it could be more explicit.

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