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

Annotations already declare readOnly, idempotent, non-destructive, so the safety profile is covered. The description adds non-obvious content beyond annotations: what fields the response contains, that public data only is returned, and that voucher codes are deliberately omitted and must be obtained on the website.

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?

Three short sentences, front-loaded with the resource and payload, then the id provenance, then the voucher caveat. Every sentence carries information; the closing website sentence is useful but slightly tangential.

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?

No output schema exists, and the description compensates by listing the returned fields and calling out what is excluded. For a single-parameter read with full annotations, the only gap is behavior on an invalid or stale id.

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 already explains the id must be the exact offer id including the country prefix. The description reinforces the provenance (from search_offers) but adds no format or syntax detail beyond the schema, so baseline 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 ('Read the full public details of one current offer') and enumerates the payload ('description, shop, savings, conditions and dates'). The reference to 'the exact id returned by search_offers' cleanly separates it from the search/list siblings.

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?

Clear context: use it after search_offers, with the exact id from that call. It also states a scope exclusion (voucher codes are not included; members reveal them on the website) which steers the agent away from requesting voucher data here. No explicit statement of when NOT to call it beyond that.

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