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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world, so the safety profile is fully covered. The description does add one real behavioral detail beyond that: phone and website appear only 'if the provider published it', signalling conditionally present return fields. It says nothing about rate limits, error behavior for missing ids, or pagination, so it adds modest rather than rich context.

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 sentence with the action and id source front-loaded, followed by a tight enumeration of return fields. Nothing is wasted and there is no filler.

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 return-value burden and does so by listing the fields the agent will receive, plus the caveat that phone/website may be absent. Combined with annotations covering safety and a fully documented single param, an agent has everything needed to call this correctly.

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?

Only one parameter, and schema coverage is 100% – the schema already says 'Offer id from search_offers.'. The description repeats that provenance but adds no new syntax, range, or format meaning. Baseline 3 for a fully documented single parameter.

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 ('Get full details') and resource ('one offer by its id') and enumerates exactly what is returned: description, price, address, website, phone, images, url. This distinguishes it cleanly from search_offers, which produces the id.

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 parenthetical '(from search_offers)' establishes the workflow: find an offer via search, then fetch its detail here. It stops short of an explicit exclusion ('do not use this to browse or filter'), so it is clear context rather than full routing guidance.

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