add_contact

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

The critical warning about the contact being created with a random email that must be changed in Invapi is non-obvious and valuable. Annotations already convey that the operation is not read-only and not destructive, and the description adds concrete post-creation behavior beyond those flags.

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 tight sentences with no filler. The warning is front-loaded after the action and earns its place, and the endpoint parenthetical is brief and useful.

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 simple one-parameter tool with a fully documented schemaaint, the description covers the essential behavioral caveat. The only minor gap is that 'Invapi' is not explained, but the overall context is sufficient for an agent to call the tool correctly.

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% and the only parameter, 'confirm', is self-describing in the schema. The description adds no parameter-level semantics, but none are really needed here since the boolean confirm parameter is fully documented.

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 ('Добавить'/'add'), a clear object ('дополнительный контакт в аккаунт'), and even includes the endpoint 'whmcs/add_contact'. This clearly distinguishes it from sibling tools like update_contact and delete_contact without needing to open their schemas.

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 usage context is implied by the verb and resource: it is for adding, not updating or deleting, a contact. However, the description does not explicitly mention alternatives such as update_contact/delete_contact, nor does it say when this tool should be preferred over them.

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