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

Annotations already establish readOnlyHint=true, destructiveHint=false, so the safety profile is covered. The description adds substantive behavioral context beyond that: it discloses the returned fields, that prices are dated by when they were checked, and that the buy verdict is derived from Comparr's recorded price history.

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 opens with the core scope ('All current offers for one product') before detailing the payload. No filler, no repetition of the title, every clause carries information.

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 no output schema, the description carries the burden of describing the return payload and does so well. Minor gaps remain: no mention of what happens when no offers or no price history exist, and no note on currency or result ordering, but nothing critical for invocation 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?

Schema coverage is 100% for the single 'product' parameter, so the schema already documents the id-or-slug format. The description only restates the identifier and hints at where to obtain it, adding no new syntax or constraint detail, so the baseline of 3 applies.

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') and then enumerates the payload an agent gets back (checked date, exact seller, condition, buy verdict). It also distinguishes itself from siblings by naming search_products and get_deals as the places the required id/slug comes from.

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 gives the precondition for calling it (you need a product id or slug from search_products or get_deals), which is real routing guidance. It does not explicitly say when to prefer this over get_deals or get_price_history, so it falls short of full when/when-not coverage.

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