Retrieve a customer

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is fully covered. The description adds the workspace-scoping constraint, but says nothing about rate limits, auth prerequisites, or behavior when the ID does not exist.

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 with the core action front-loaded and no filler. The second sentence largely duplicates the schema's own `id` description, a minor redundancy rather than padding.

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 simple read-only lookup, the description plus annotations and a fully documented schema give an agent everything needed to invoke it. The absence of an output schema means the response shape is unspecified, though that is a minor gap for a get-by-ID tool.

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%, so all three parameters (id, account, include_expanded_fields) are already documented in the schema. The description's `ext_` prefix note restates what the `id` schema description already says, adding no new meaning.

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 and resource ('Retrieve a customer') plus a scope constraint ('for the authenticated workspace'). It is clearly distinguishable from sibling list_customers, update_customer, and delete_customer without opening any schema.

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?

Usage is implied: fetch a single customer when you have an identifier, versus list_customers to enumerate. The only explicit guidance is the `ext_` prefix for external IDs. No alternatives or preconditions are named, so it stays at the minimum-viable level.

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