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

Annotations only carry destructiveHint=true, and the description adds real behavioral context: the WRITE marker aligned with the destructive hint, PATCH-style partial-update semantics ('Only the fields you pass change'), and an explicit list of non-settable fields. It omits auth/permission requirements and any failure behavior for an invalid customer_number.

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 tight sentences, front-loaded with the WRITE marker and the core action, then the partial-update rule, then exclusions, then the endpoint. No filler and nothing buried.

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 32-parameter mutation with no output schema, the description covers the essential risks: it is a write, it is partial, and certain fields are off-limits. Missing only permission prerequisites and error/not-found behavior, which keeps it short of a full 5.

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 32 parameters at 100% schema description coverage, the schema already defines every field, so baseline is 3. The description adds only the meta-rule that unspecified fields are left unchanged and that balances/credit limit/custom fields cannot be passed, which is marginal but genuine added value.

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 ('update fields on an existing customer') and immediately differentiates itself from the create/get siblings by scoping to an existing customer. The PATCH endpoint confirms the operation type without ambiguity.

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 ('existing customer', partial update by passing only changed fields) but no alternative is named explicitly, e.g. it never says to use kickserv_create_customer for new records or kickserv_get_customer to read first. The negative constraints (balances, credit limit, custom fields not settable) are useful but are limitations rather than when-to-use guidance.

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