Create or update customer

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

The description adds a valuable privacy warning about writing personal data, which goes beyond annotations. It also clarifies the create/update distinction. However, it does not disclose whether updates are partial or full replacements, which is a significant behavioral gap.

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 sentences with no filler, front-loading the core purpose and including a crucial privacy caveat. Each sentence earns its place.

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 tool with 11 parameters and no output schema, the description is under-specified. It lacks details on update behavior, required field validation, and return values, and does not guide the agent on partial updates or idempotency beyond what annotations provide.

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 only 27%, so the description must compensate for the many undocumented parameters. It only mentions 'id' and provides no additional meaning for the other 10 parameters, leaving agents to guess at semantics for fields like city, note, or region.

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 tool creates or updates a customer, with an explicit mention of using the id for updates. It differentiates from sibling tools like get_customer or list_customers by focusing on the upsert action.

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 implies usage (when you need to create or update a customer) but provides no explicit guidance on when not to use it or which alternative tools to use for read-only operations. The privacy note adds a usage constraint but doesn't address tool selection.

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