update_customer

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

Annotations already indicate readOnlyHint=false and destructiveHint=false. The description adds 'Edit' (a write operation) and the return value '{success}', but does not disclose additional behaviors such as idempotency, authorization requirements, or side effects beyond the partial update characteristic.

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 concise sentences. First sentence encapsulates purpose and identification method. Second covers partial update behavior and return value. No wasted words and front-loaded.

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?

Given the 11 simple parameters and full schema coverage, the description is sufficient. However, it could mention that the customer must exist, or that some fields may be conditionally required based on site settings. No output schema, but return value is specified.

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 100% schema description coverage, baseline is 3. The description adds value by noting that only passed fields are sent (partial update) and that identification can be by id or externalId, which informs the 'by' parameter usage beyond its schema description.

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 clearly states the verb 'Edit', the resource 'existing customer', and the identification method 'by id or externalId'. It lists the updatable fields (name, email, phones, address), which distinguishes it from customer creation or retrieval tools among siblings.

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 use when modifying an existing customer but does not explicitly state when to use this tool versus alternatives like create_customer or merge_customers. No exclusion or prerequisite conditions are provided.

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