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

No annotations exist, so the description carries the behavioral disclosure burden. 'Fetch' implies a read-only retrieval, but the description does not state what happens for missing ids, permissions, rate limits, or any side effects. This is acceptable for a simple getter but not richly transparent.

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?

One sentence, no filler, and the core scoping detail is front-loaded. Every word contributes.

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?

For a one-parameter getter, the description covers the tool's purpose and id provenance. It could add not-found or response-shape details since no output schema exists, but the tool is simple enough that these are not critical gaps.

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?

The schema only exposes a string 'offer_id' with no description; the description adds meaningful context by saying the id comes from search_offers. This tells an agent where to obtain a valid offer_id, which is important with 0% schema coverage.

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?

Description uses a specific verb 'Fetch' with a clear resource, 'one offer by its id', and differentiates itself from search_offers by indicating it retrieves a single existing offer rather than searching. Sibling ambiguity is minimal.

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)' gives useful context: the agent should first run search_offers to obtain the id, then call get_offer. It does not explicitly state when not to use it, but the by-id nature makes the usage context clear.

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