create-customer-contact

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

No annotations are provided, so the description carries the disclosure burden. It does reveal that the operation is a mutation (POST) and the required scope (customers:write), which is genuinely useful. However, it does not disclose the return value on success, error behavior, or whether creating a second isPrimary=true contact affects existing contacts.

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?

One dense sentence with zero fluff: purpose, endpoint, and scope in a single line, with the verb front-loaded. Every element 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?

Given 5 params, no annotations, no output schema, and only 20% parameter coverage, the description is too sparse: no return information, no note that customerId must reference an existing customer, and no parameter semantics. An agent can guess the basics but will be uncertain about outcome and edge behavior.

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 20% — customerId is the sole parameter with a description. The description adds no meaning for name, email, phone, or isPrimary, and the isPrimary semantics (e.g., what happens if another contact is already primary) are entirely unexplained.

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+resource ('Create a contact on a customer') and reinforces it with the exact endpoint (POST /api/public/customers/{customerId}/contacts). The name and description clearly separate it from siblings like create-customer, list-customer-contacts, and update-contact.

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?

No explicit when/when-not guidance and no mention of alternatives such as update-contact for existing contacts or list-customer-contacts for reading. Usage must be inferred from the name and the 'create' verb, and the prerequisite that the customer already exists is unstated.

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