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

Annotations are absent, so the description carries the full disclosure burden and provides almost none of it. It doesn't say whether omitted fields are left untouched or cleared (patch vs replace), whether changes are reversible, what permissions or auth are required, or what the call returns on success/failure.

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?

One compact sentence with the verb and resource front-loaded and no filler. Brevity is appropriate here, though it comes at the cost of the missing semantics noted elsewhere.

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 10-parameter mutation with a nested object, zero annotation coverage, and no output schema, the description is far too thin. An agent can identify the tool but cannot confidently determine update semantics or side effects from the definition alone.

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% across 10 parameters, including a nested billing_address object and an enum for 'kind'. The description maps field names to business concepts but adds no format, validation, or behavior semantics — e.g., that customer_id is the required key, that billing_address is a structured sub-object, or the meaning of the person/company enum.

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?

Specific verb ('change') plus resource ('customer') with an enumeration of the mutable fields, which is more than a restatement of the name. It does not, however, distinguish this from look-alike siblings such as customers_contactUpdate or customers_merge, so an agent must still infer which one applies.

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 statement of when to use this versus customers_contactUpdate, customers_merge, or customers_archive. Nothing about prerequisites (does the customer need to exist / be unarchived) or whether partial updates are supported.

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