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

Annotations declare non-readOnly, non-destructive, openWorld. The description adds genuinely useful context beyond that: no message reaches the contact, so no confirmation prompt is needed, and it returns a contact_id. It also names the required auth (Cotlet API key with app access).

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 purpose is front-loaded, but the two sentences 'Nothing is sent to the person' and 'It reaches no one, so it runs without asking' restate the same point, adding redundancy rather than new information.

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 create tool with no output schema, the description is largely complete: it covers the write semantics, the no-notification behavior, the returned contact_id, and the auth requirement. Minor gaps remain around duplicate handling or error behavior, but these are not critical.

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 100%, so the schema already documents name, email, phone, and type. The description adds no parameter-level syntax or format guidance, which is the expected baseline when the schema does the heavy lifting.

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 states a specific verb and resource: 'Add a client or lead to Studio Manager contacts' and 'Adds one contact to Studio Manager.' An agent can distinguish this creation tool from read siblings like pixieset_list_contacts without opening the schema, though no other create sibling is explicitly named or excluded.

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 by noting 'Nothing is sent to the person... so it runs without asking,' which signals this is a safe, no-notification action. However, it never states when to prefer this over alternatives or any prerequisite beyond the API key, leaving routing to inference.

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