Upload receipt images to match with expenses in the Brex financial platform. Submit base64-encoded image data with file name and MIME type for expense tracking.
Upload a receipt image to match with expenses
| Name | Required | Description | Default |
|---|---|---|---|
| receipt_data | Yes | Base64-encoded image data | |
| receipt_name | Yes | Name of the receipt file (e.g., 'receipt.jpg') | |
| content_type | Yes | MIME type of the receipt (e.g., 'image/jpeg') |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries full burden but offers minimal behavioral insight. It states the upload purpose but doesn't disclose permissions needed, rate limits, whether this creates a new expense record, how matching works, or what happens on failure. For a mutation tool with zero annotation coverage, this is inadequate.
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, efficient sentence that directly states the tool's purpose without unnecessary words. It's appropriately sized for a straightforward upload operation and front-loads the core action.
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 tool with no annotations and no output schema, the description is insufficient. It doesn't explain what happens after upload (e.g., returns a match ID, creates an expense), error conditions, or system behavior. The agent lacks critical context to use this tool effectively.
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%, providing complete parameter documentation (base64 data, filename, MIME type). The description adds no parameter-specific information beyond what's in the schema, so it meets the baseline for high schema coverage without compensating value.
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 clearly states the action ('Upload') and resource ('a receipt image'), with the purpose 'to match with expenses' providing specific context. It distinguishes from most sibling tools (which are primarily 'get' operations), though it doesn't explicitly differentiate from 'match_receipt' which appears related.
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 provides no guidance on when to use this tool versus alternatives like 'match_receipt' or 'update_expense'. It doesn't mention prerequisites, sequencing, or exclusion criteria, leaving the agent to infer usage context from the purpose alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.