Update selected fields on an existing invoice, including items, dates, notes, reference number, or template. Modify invoice details directly without recreating the document.
Update fields on an existing invoice.
| Name | Required | Description | Default |
|---|---|---|---|
| items | No | ||
| notes | No | ||
| due_date | No | ||
| invoiceId | Yes | ||
| invoice_date | No | ||
| template_name | No | ||
| reference_number | No |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds nothing beyond the word 'update' – it doesn't disclose whether this is a partial update (only specified fields changed) or a full replacement, nor does it mention that unspecified fields remain untouched. This is a significant behavioral gap for a mutation 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 description is a single short sentence, which is concise and front-loaded with the core action. However, it is under-specified; it doesn't provide any of the details an agent needs. While it is not verbose, it sacrifices usefulness for brevity, making it merely adequate in structure.
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?
With 7 parameters, one required, and no output schema, the description should provide more context. It doesn't mention whether updating is partial, what happens to missing fields, error conditions, or any preconditions. The schema alone is insufficient, and the description does not fill the gap, making the tool incomplete for reliable use.
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% for most properties (only 'price' has a description). The description does not compensate by explaining any parameter meaning – it only says 'Update fields' without listing or elaborating on any of the 7 parameters. The agent must rely on the bare schema names, which is insufficient for correct invocation.
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 uses a specific verb ('Update') and a specific resource ('existing invoice'), making the core action clear. However, it doesn't differentiate itself from sibling tools like update_estimate beyond the resource name, which is obvious from the name itself. It also doesn't specify which fields can be updated, leaving the agent to infer from the 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?
No guidance is given on when to use this tool versus alternatives. It doesn't mention that an invoice must already exist (require invoiceId) or that you should fetch the invoice first. No exclusions or alternative tool recommendations are provided, leaving the agent to guess when this is appropriate.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.