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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds nothing beyond that: no behavior for a missing or deleted customer, no note on what fields are returned, no scoping (account/workspace) constraints. With annotations doing all the work, the description earns only minimal credit.

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?

A single short sentence with the verb and resource front-loaded - nothing wasted, nothing padded. It is efficient, though efficiency here is partly a product of extreme under-specification.

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 one-parameter read tool with rich annotations and no output schema, the description is minimally sufficient to call it correctly. However, it omits how to obtain the id and what happens on a not-found result, which are the two questions an agent actually has here.

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 100% for the single 'id' parameter, so the schema already carries the documented meaning and the baseline of 3 applies. The description adds no format, source, or validation detail (e.g. whether id is the internal customer id or an external identifier).

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 names a specific verb and resource ("Retrieve a customer"), which is slightly more than the title restating itself, but it does nothing to distinguish this from close siblings such as list_customers, get_customer_usage, or get_contact. An agent still has to infer that this fetches one record by id rather than an aggregate or usage report.

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?

There is no when-to-use guidance, no mention of the alternative list_customers for enumerating customers, and no note on prerequisites such as needing a customer id obtained elsewhere. The agent is left to infer selection criteria from the name alone.

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