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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is carried structurally. The description adds one genuinely useful behavioral fact — the structured error contract with retry_recommended and retry_after_seconds — which informs retry logic. However it says nothing about history depth, granularity, or result caps, and the error shape is likely already reflected in the output schema.

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 sentences, purpose front-loaded, no filler. The second sentence is a dense field enumeration, but each listed field carries retry-relevant information, so 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?

With a full output schema, complete input schema coverage, and annotations covering safety, the description supplies what structured fields do not: the returned content categories and the failure/retry contract. Nothing required to invoke it correctly is missing.

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?

There is a single required parameter with 100% schema description coverage ('Public product ID'), so the schema already does the work. The description does not mention product_id or clarify that it is a public (not internal) identifier, adding no meaning beyond the schema — baseline 3.

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?

Specific verb+resource with the returned content enumerated (historical prices, aggregates, trend, data points) for a product. It does not explicitly contrast with siblings like get_product or search_products, which also surface product data, but the 'history/aggregates/trend' framing is distinctive enough to select on.

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 use case (fetching price history for a known product) is implied by the description but never stated as when-to-use, and no alternative or prerequisite (e.g. resolve product_id via search_products first) is mentioned. Adequate minimum-viable guidance only.

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