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 valuable context beyond this: partial-update behavior ('Only the fields you pass are sent') and the return shape ('Returns {success}'). It does not conflict with annotations and provides meaningful transparency for a non-destructive update operation.

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?

The description is two sentences, front-loaded with the action and resource, and every word contributes. It states the scope, lookup options, partial-update behavior, and return value with zero waste.

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 an 11-parameter tool with no output schema, the description provides essential context: lookup method (id/externalId), partial update semantics, and return type. It omits the multi-site 'site' nuance, but that is already covered in the schema's parameter description, so the tool definition remains adequately complete.

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 is 3. The description adds the crucial semantic that only provided fields are sent, which clarifies the optional nature of all non-required parameters and how updates merge with existing data. This goes beyond the schema's per-field descriptions.

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 uses a specific verb ('Edit') with a clear resource ('existing customer') and enumerates updatable fields (name, email, phones, address). It distinguishes from sibling tools like create_customer and merge_customers by explicitly targeting existing customer updates and supporting lookup by id or externalId.

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 clearly implies use when editing an existing customer, and the partial-update statement ('Only the fields you pass are sent') provides key usage guidance. It does not explicitly name alternatives or exclusions, but the sibling tool names (create_customer, merge_customers) make the intended use case obvious.

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