Get customer

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

'Read-only' merely restates the readOnlyHint annotation, so it adds no value beyond the structured data. The description does not disclose what happens when the id doesn't exist (error vs empty), whether results are cached, or any auth requirements.

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?

Two short sentences, front-loaded with the core action, nothing extraneous. Slight waste in repeating the read-only fact already covered by annotations.

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-param read tool with no output schema, this is nearly adequate, but the missing not-found/error behavior leaves an agent unable to predict the failure mode when the id doesn't match a customer.

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%, so the description must carry the param burden, and it does so only minimally by indicating the customer is looked up 'by id'. It doesn't clarify that the id is the customer identifier (vs e.g. a booking id) or discuss valid ranges.

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 specific verb ('Fetch') and resource ('a single customer'), and the word 'single' implicitly distinguishes it from the sibling list_customers. It's clear but never names or contrasts with the sibling explicitly.

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 on when to use this versus list_customers or any other sibling. The agent must infer that this is for retrieving one known customer by id rather than enumerating customers.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.