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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false), so the description's value is in disclosing the payload: price-check dates, exact seller, condition, and a computed buy-timing verdict. That is meaningful behavioral context, especially since there is no output schema. It omits error behavior for unknown slugs and any freshness/latency caveats.

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?

A single front-loaded sentence that identifies the resource first, then enumerates the returned fields, all of which matter because there is no output schema. No filler or 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?

With one required parameter and no output schema, the description carries the burden of describing returns, and it does so with a concrete field list and the verdict's provenance ('computed from Comparr's recorded price history'). Minor gaps remain around error cases and result ordering/pagination.

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 coverage is 100% and the schema only says 'Product id or slug.' The description adds provenance for that value (obtained from search_products or get_deals), which is genuine meaning beyond the schema. Baseline would be 3; the sourcing hint lifts 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?

States a specific verb and resource ('All current offers for one product') plus the scope of the result set, which distinguishes it from the multi-item siblings get_deals and search_products. Sibling differentiation is implicit rather than explicit, but an agent can tell this is the single-product detail lookup.

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?

It tells the agent where the product id/slug comes from (search_products or get_deals), which is useful upstream routing, but it never says when to prefer get_deals or get_price_history over this tool. Usage is implied by the resource scope rather than stated.

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