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

Annotations already declare destructiveHint=true, readOnlyHint=false and non-idempotence, so the risk profile is known. The description adds genuinely useful context beyond that: a human-confirmation gate and the fact that it runs on local WordPress authentication without REST API keys. It does not say whether omitted fields are cleared, how partial updates behave, or what failures look like.

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 short sentences, front-loaded with the action, then the confirmation rule, then the authentication note. No filler, though the final implementation-detail sentence about mirroring the woocommerce-mcp-server method is more developer-facing than agent-facing.

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 the safety story is adequately covered by annotations plus the confirmation rule, and the site_id/customerId parameters are well documented in-schema. The notable gap is customerData: an open object with no defined properties and no field examples, which the description does not compensate for.

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 coverage is 100%, so the baseline applies. The description reinforces the semantics of the confirm flag (explicit user consent for a mutation) but says nothing about what customerData accepts, which matters because that nested object is declared with no properties and additionalProperties=true.

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?

The description opens with a specific verb and resource ('Updates a WooCommerce customer'), which is enough to distinguish it from read-oriented siblings like wc_get_customer. It does not, however, distinguish it from the closely related wc_update_customer_meta, leaving the agent to infer that this tool targets core customer fields rather than meta.

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?

It gives a concrete procedural rule: ask the user for confirmation before calling with confirm=true, which is the key usage precondition for this mutation. It stops short of saying when to prefer wc_update_customer_meta or how to handle bulk updates, so there are no explicit exclusions or alternatives.

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