concur_attach_receipt

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

Annotations only say readOnlyHint=false, destructiveHint=false, openWorldHint=true; the description adds far more — the refusal condition, the post-write re-read, the two-phase confirmation fallback with confirmToken, and MCP_CONFIRM_MODE behavior. It also adds prompt-injection guidance, warning the agent not to act on instructions found inside tool results, which is behavior no annotation can express.

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 dense paragraph, correctly front-loaded with purpose and precondition before the alternatives and the confirmation mechanics. Every sentence carries information, though the confirmToken explanation overlaps with the schema description and could be trimmed without loss.

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 mutation with side effects and a nontrivial confirmation protocol, it covers preconditions, alternatives, undo, confirmation modes, and what happens after the write ('Re-reads the expense afterwards'). No output schema exists, and the description supplies enough about the result to set expectations.

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%, so every parameter including confirmToken is already documented in the schema. The description restates the confirmToken lifecycle (preview then repeat call) and the imageId provenance, but adds little syntactic or semantic detail beyond what the schema already provides. 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?

States a specific verb and resource ('Attach a receipt image ... to an expense') plus the exact precondition ('an expense that has no receipt yet'). It explicitly separates itself from concur_append_receipt, concur_detach_receipt, concur_upload_receipt, and concur_list_available_receipts, so an agent can route without opening any schema.

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?

Gives explicit when-to-use, when-not-to-use ('an expense that already has one is refused'), the named alternatives for each branch (append_receipt, or detach first), and the undo path (concur_detach_receipt). It also states the confirmation prerequisite, which is the main reason a call would fail or stall.

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