Polar Daily Training Summary

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint. The description adds 'non-medical' context and mentions graceful handling of missing data ('when available'), which goes beyond annotations without contradicting them.

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 extremely concise, using two short sentences to convey purpose, data sources, and safety. Every word serves a purpose with no redundancy.

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 output schema exists and annotations are rich, the description adequately covers the tool's function. However, it lacks specifics about the summary contents (e.g., format or key metrics), which would slightly improve completeness.

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 provides clear descriptions for all three parameters (days, timezone, response_format) with 67% coverage. The description adds no further parameter details, so it meets the baseline expectation without exceeding it.

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 ('Build') and the resource ('practical daily summary') from specific data types (sleep, activity, Nightly Recharge, training). It also clarifies it's read-only and non-medical, and distinguishes from siblings that list raw data by offering an aggregated summary.

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 daily summaries ('when available') but does not explicitly state when to use this tool vs alternatives like polar_weekly_summary or polar_wellness_context. There is no guidance on when not to use it or which sibling to prefer for different needs.

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