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

With no annotations provided, the description carries the full burden of disclosing behavioral traits. 'Fetch' implies a read operation, but the description does not explicitly state side effects, permissions, error behavior, or what happens if the id is not found. Minimal disclosure leaves the agent with uncertainty.

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?

The description is a single sentence of eight words, front-loaded with the action and target. It contains no filler or redundant information and is appropriately sized for a simple fetch-by-id tool.

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?

Given the tool's simplicity (one parameter, output schema exists), the description covers the core functionality. However, it lacks context about error handling or prerequisites for the id, making it only minimally complete. The output schema presumably covers return values, so that is not a gap.

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 has one required parameter (receipt_id) with no description, and schema description coverage is 0%. The description's 'by id' adds only that the parameter is an identifier, but does not explain its format, origin, or any constraints. This offers minimal value beyond the schema's property title.

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 uses the action verb 'Fetch' with a specific resource ('single delivery receipt') and scope ('by id'), clearly indicating the operation. It distinguishes from sibling tools like verify_receipts by emphasizing 'single' and 'fetch' versus verification, though it does not explicitly name alternatives.

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?

No guidance is provided on when to use this tool versus alternatives such as verify_receipts. The only implied context is that it is used when a receipt id is available, but no exclusions or alternative scenarios are described.

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