Note something on a customer. Money is integer minor units (cents). Calling this changes nothing: it returns a preview of what would change and a confirmation link. Only the merchant, on that page, can make it happen.
| Name | Required | Description | Default |
|---|---|---|---|
| note | Yes | What the file should say. With append, the line to add below what is there. | |
| Yes | |||
| append | No | Add below the existing note instead of replacing it. |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Goes well beyond the annotations by disclosing the two-step flow: the call only returns a preview plus a confirmation link, and only the merchant on that page can commit the change. The only friction is the dangling 'Money is integer minor units (cents)' sentence, which is irrelevant to a tool with no monetary parameter and reads like a copy-paste artifact.
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?
Three short sentences, front-loaded with the core action and the no-side-effect caveat. The money-units sentence is dead weight that could be removed 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 no-output-schema mutation tool, the description covers the essential behavior: what happens on call, what the caller receives, and who can finalize. Only minor gaps remain (what the preview contains, error/edge behavior).
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 67%; the schema already documents 'note' and 'append' in detail, and the description adds nothing about these parameters. The money-units sentence does not map to any actual parameter, so it adds no real semantics.
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 concrete verb+resource ('Note something on a customer') that an agent can immediately distinguish from customers_message, customers_lookup, or orders_note. It is clear but never explicitly names or rules out those siblings.
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?
It explains that the call itself is a no-op pending confirmation, but gives no guidance on when to prefer this over customers_message or orders_note, nor any prerequisites (e.g., customer must exist). Context is implied at best.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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