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

Annotations already declare readOnlyHint=false, destructiveHint=true, idempotentHint=false, and openWorldHint=true, so the safety profile is covered structurally. The description adds a useful precondition about the customer existing, but repeats 'write operation' (already implied) and says nothing about the required `confirm` flag, reversibility, or 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?

Three compact sentences, front-loaded with the action and endpoint, then scope, then limitations. No filler; each sentence carries information, though the 'write operation' note is mildly redundant with 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 non-idempotent mutation with no output schema, the description covers the endpoint, updatable fields, and the existence precondition. It leaves the confirm requirement and credential parameters to the schema, which is acceptable but slightly thin for a destructive operation.

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 67% and 9 params exist; the description names name and custom_fields and embeds customer_id in the path, which is useful. It does not explain the confirm flag (schema does), the auth options, or account_id multi-workspace behavior, so it stays at the baseline for a partially-documented 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+resource ('Updates an existing customer') and even names the endpoint and the two mutable areas (name, custom field values). It does not, however, explicitly differentiate itself from the other customer mutators (archive_customer, delete_customer, restore_customer), so sibling disambiguation is only partial.

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?

Provides a precondition ('customer must exist in the target account') and flags it as a write operation, which implies context of use. But there is no explicit guidance on when to choose this over create_customer, archive_customer, or delete_customer, so usage is only implied.

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