concur_create_expense

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

Goes well past the annotations: it discloses the preview/confirmToken two-step fallback, MCP_CONFIRM_MODE behavior, that missing required fields are saved with exceptions rather than failing, that over-length text is refused, that list fields are resolved to a list item, and that a non-report currency triggers Concur's own exchange rate. The prompt-injection warning also tells the agent when it must NOT execute, which is unusually valuable for a write tool.

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 core action is front-loaded and most sentences carry real content, but it is a single dense paragraph with repeated confirmation/prompt-injection caveats that could be tightened. The last sentence restates the confirmToken rule already given earlier.

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 14-parameter mutation with a nested free-form fields object and no output schema, the description covers the confirmation protocol, what the preview returns, how partial success is reported, and how auxiliary parameters resolve. An agent has everything it needs to call this safely in one pass.

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 coverage is 100% and the schema descriptions are already rich (per-field formats, defaults, the fields-by-label mechanism), so much of the description restates structured data. It still adds framing the schema does not, notably the currency/exchangeRate interaction and that required empty fields surface as exceptions rather than blocks.

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?

Opens with a specific verb+resource and a precondition that separates it from siblings: "Add an expense to an unsubmitted SAP Concur report." An agent can distinguish it from concur_update_expense, concur_create_report, and concur_copy_expense immediately from the first sentence.

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?

Names the helper tools that supply each lookup value (concur_list_expense_types for type, concur_search_locations for locationId, concur_list_payment_types, concur_list_reports) and states the unsubmitted-report precondition plus a strict when-to-invoke rule around user confirmation. It does not explicitly say when to prefer this over concur_update_expense or concur_upload_receipt for an existing item, but the context it does give is strong and actionable.

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