Fetch a customer's details by their numeric ID to access account information needed for support interactions.
Fetch a customer by their id.
Args:
customer_id: The customer's numeric id.
| Name | Required | Description | Default |
|---|---|---|---|
| customer_id | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The verb 'Fetch' clearly indicates a read operation主食, but with no annotations and no further description, behavioral details such as null/not-found behavior, return format, or error handling are absent. The description is not misleading, but it relies on the tool name's implication of read-only.
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 exceptionally concise and front-loaded: 'Fetch a customer by their id.' The argument documentation is immediately after and minimal. No wasted words.
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 single-parameter getter, the description covers the essential information: what resource and what key. It lacks explicit mention of behavior when the customer is not found or of the return value, but those are not necessary for a simple id-keyed fetch and the sibling tools make the context clear.
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 schema provides the parameter name and type (integer), and the description only restates that it is a numeric id. It adds no meaning beyond the schema, such as where to find the id, uniqueness, or format constraints. With 0% schema description coverage, the description should compensate but does not.
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 precise verb-resource pair: 'Fetch a customer by their id.' It clearly identifies the operation, the resource, and the lookup key. This differentiates it from siblings like list_customers_tool (plural) and create_customer_tool (write operation).
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 makes it clear this is for retrieving a single customer when the id is known. It doesn't explicitly mention when not to use it or name alternatives, but the context is unambiguous given the sibling tool names.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.