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

Annotations already establish the safe read-only, non-destructive, open-world profile. The description adds genuinely new operational context: that a "terms last verified" field exists (data recency) and that money amounts should be quoted verbatim rather than paraphrased. It does not cover behavior on a missing/invalid id.

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, zero waste, with the usage trigger front-loaded ahead of the field list. The dense enumeration of returned fields is information-bearing rather than 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?

An output schema exists, so return values need no explanation, and annotations carry the safety profile. The description covers when to call it and what it yields; only error/not-found behavior for an invalid id is unaddressed, a minor gap given the otherwise complete coverage.

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 description coverage is 100% and the single id parameter is already documented with a concrete example plus a pointer to search_bonuses for discovery. The description adds nothing further about the parameter, so the 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?

The description makes clear this tool reads the full detail of a single offer, enumerating the exact fields returned (requirements, minimum deposit, direct-deposit rules, expiry, state availability, verification date). It distinguishes itself implicitly from search_bonuses via the id lookup, but never names the sibling it is not, so 4 rather than 5.

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?

"Use before recommending an offer" gives a concrete workflow trigger, which is strong guidance for an agent. It stops short of naming alternatives (e.g. search_bonuses for discovery, compare_bonuses for side-by-side) or stating exclusions, so it falls just below the explicit when/when-not bar.

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