Record a trip expense with category, decimal amount, payer, and date; attach an optional local receipt for later claim review.
Write an expense and copy an optional local receipt. Money is a decimal string.
| Name | Required | Description | Default |
|---|---|---|---|
| note | No | ||
| amount | Yes | ||
| nights | No | ||
| paid_by | No | employee | |
| receipt | No | ||
| trip_id | Yes | ||
| expense_date | No | ||
| travel_class | No | ||
| category_name | Yes |
Changes observed during successful MCP inspections.
v0.1.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It discloses that this is a write operation and that a receipt file is copied locally, but says nothing about required permissions, duplicate handling, what the tool returns (e.g., a new expense id), or whether the trip must already exist.
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?
Two short sentences with no filler, and the money-format rule is stated plainly. The receipt clause ("copy an optional local receipt") is slightly awkwardly phrased and would read better as "receipt is a local file path that will be copied".
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 9-parameter mutation tool with no annotations, no output schema, and no schema coverage, the description is far too thin. It omits return value, defaults behavior, unit semantics for nights/amount, and any validation or error conditions.
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 0% across 9 parameters, so the description should compensate and does so only for two: amount ("decimal string") and receipt (optional local file to copy). Critical fields like nights, paid_by, expense_date, travel_class, and category_name receive no explanation of format or semantics beyond their titles.
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?
"Write an expense" gives a specific verb and resource, so an agent knows this creates an expense record. It does not distinguish itself from siblings like add_trip or build_claim beyond the resource noun, but the purpose is unambiguous.
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 statement of when to use this versus add_trip, build_claim, or the claim-listing tools, and no prerequisites such as whether trip_id must reference an existing trip. The agent must infer usage entirely from the name.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.