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

All annotations are false, so the description carries the behavioral burden. It does add valuable traits: the tool requires a filesystem, is unusable on hosted endpoints, and reads/hashes a receipt file. However, it does not disclose side effects such as whether an existing receipt is replaced, or what the return/result looks like. There is no contradiction with the annotations.

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 front-loaded with the critical limitation, then gives actionable installation instructions and a fallback. It is longer than a typical tool description due to the URL and steps, but every sentence serves a practical purpose. No fluff.

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 simple two-parameter tool with a fully documented schema, the description supplies necessary environment context: local-only availability and the filesystem requirement. It also provides a workaround for hosted users. It could be more complete with an explicit statement of the operation and its effect on the expense record, but an agent has enough to decide whether and how to call it.

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%, with both id and path fully documented in the input schema. The tool description adds no parameter-level meaning beyond what the schema already provides, so the baseline score of 3 is appropriate.

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 title 'Attach a receipt' conveys the action, but the description leads with an availability warning and never explicitly defines the core function such as 'attaches a receipt file to an expense.' The schema clarifies the attachment target, but the description alone is more about when the tool cannot be used than what it actually does. It also does not distinguish the operation from sibling tools like expense_update.

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 description explicitly states when the tool cannot be used ('Not available on the hosted endpoint'), provides a concrete alternative path (local install with a download URL and instructions), and offers a non-tool fallback ('record the receipt reference in the expense note'). This is strong when/when-not guidance, though it does not mention sibling tools by name.

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