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

readOnlyHint=true already establishes this as a safe, non-mutating read. Beyond that, the description usefully discloses that the payload includes prices and attached benefits (inline expansions an agent would otherwise not predict). It does not mention rate limits or not-found behavior, so the addition is modest.

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?

Two short sentences, zero padding, with the core purpose front-loaded ahead of the endpoint reference. Every element 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?

A simple one-parameter read-only tool with full schema coverage and annotations covering its safety profile. The only real gap is that no output schema exists, and the description partially compensates by naming the included prices and benefits, but does not describe the overall response shape.

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 100% for the single required product_id, so the schema already documents the parameter. The description adds only the REST path mapping (GET /v1/products/{id}), which mildly reinforces that the id is a path parameter but adds no semantic meaning 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?

Clear specific verb+resource: 'Fetch a single product'. It also adds the enrichment scope (prices and attached benefits), which tells the agent this is not a bare record fetch. It does not name the sibling it contrasts with (polar_list_products), so differentiation is implicit in the word 'single' rather than explicit.

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?

No when-to-use guidance and no alternatives named. An agent must infer that this is for fetching one known product by id versus using polar_list_products to enumerate. No prerequisites or error conditions are mentioned.

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