Polar Demo

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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description's key added value is disclosing that the returned payloads are synthetic examples rather than real data — an important behavioral fact not in the annotations. It does not mention auth requirements or that only three of many tools are covered.

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?

One front-loaded sentence with the verb+resource first and the rationale second. No filler; the list of covered tools is the only detail and it earns its place.

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?

There is no output schema, so the description should carry more of the return-shape burden. It says payloads exist but not whether all three are returned together, how they are keyed, or how response_format affects the output. Adequate for a simple read-only demo tool, but with clear gaps.

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 description coverage is 0% and the single parameter (response_format, enum markdown/json, default markdown) is never mentioned in the description. With one enum parameter carrying a default, the description should clarify output format behavior but does not compensate for the coverage gap.

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?

States a specific verb (returns) and a specific resource (example payloads), and names the exact three sibling tools whose contracts it mirrors (polar_daily_summary, polar_wellness_context, polar_list_nightly_recharge). An agent can immediately tell this is a preview/sample tool rather than a live data fetch.

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 clause 'so agents see the contract before calling real Polar APIs' gives clear usage context: call this first to inspect shape, then call the real tools. There are no explicit exclusions or alternatives for the ~27 other siblings whose contracts are not demoed, so it stops short of a 5.

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