Retrieve a mock customer record by entering a valid customer ID (format: CUST-#####). Use this to fetch customer data from the gateway server.
Fetch a mock customer record
| Name | Required | Description | Default |
|---|---|---|---|
| customer_id | Yes |
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 the full burden of behavioral disclosure. It mentions 'mock' and 'fetch', implying a read-only operation, but does not state side effects, error behavior, return format, or whether the record is guaranteed to exist. The description adds minimal behavioral context.
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, concise sentence with no redundant information. It front-loads the core action and resource, making it efficient to parse.
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?
Given the tool's simplicity and lack of output schema, the description is too sparse. It does not explain what a 'mock customer record' contains, how errors are handled, or what the agent should do with the result. An agent calling this tool would have to infer these details from elsewhere.
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?
The description does not mention the 'customer_id' parameter at all, and schema description coverage is 0%. Since the description is the only source of parameter context, its silence leaves the parameter meaning entirely to the schema's pattern and constraints, which is insufficient for an agent to know how to construct a valid request beyond the literal pattern.
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 states a clear verb 'Fetch' and a specific resource 'mock customer record', which distinguishes it from the sibling 'trigger_refund'. It is unambiguous about what the tool does.
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 provided on when to use this tool versus alternatives. The sibling tool is named but not referenced in the description, leaving the agent to infer usage context without any explicit cues.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.