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

Adds meaningful behavioral detail beyond annotations: only whitelisted keys are accepted, invalid keys cause nothing to be written, and null is refused for type/title. This clarifies atomicity and validation beyond the destructive/idempotent hints.

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 tightly written sentences with the key constraints front-loaded. Every clause adds necessary information without repetition.

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 destructive mutation with annotations covering safety and idempotency and no output schema, the description provides enough constraints to call it correctly. Remaining details like exact return behavior or permissions are minor given the structured metadata.

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?

With 0% schema description coverage, the description compensates by naming the allowed keys for the required updates object and explaining the two customer locator parameters. It still leaves value types and the updates object shape implicit, but substantially clarifies the otherwise undocumented schema.

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 (Update) and resource (allowed keys of a customer), and lists the exact allowed keys. This clearly scopes the operation, though it does not explicitly differentiate from the sibling edit_customer tool.

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 implies usage by listing allowed keys and stating that any other key is refused, but it does not explicitly say when to use this tool instead of edit_customer or other customer update tools.

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