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

The annotations already disclose that this is a non-read-only, non-idempotent, non-destructive, closed-world mutation. The description adds little behavioral detail beyond saying it creates a contact with name, email, and phone; it does not mention duplicate risk, approval_id workflow, or conflict handling. There is no contradiction with the annotations.

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 compact sentences with no wasted text. It front-loads the usage trigger and follows with the creation behavior, and the example adds useful clarity without bloating the definition.

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?

An output schema exists, annotations cover the safety profile, and the input schema fully documents parameters. The description gives the trigger and basic fields, but it could add context about duplicate checks or approval handling. That gap keeps it from a 5.

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 input schema already documents all five parameters, including approval_id. The description mentions name, email, and phone but omits last_name and approval_id, so it adds little beyond the schema baseline.

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: it creates a contact, and the example clarifies this is for a newly introduced person. It does not differentiate itself from nearby siblings such as contacts.update, contacts.import, or contacts.merge, so it falls short of a 5.

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 gives a clear usage trigger: when the user introduces a new person who should be remembered. It does not say when not to use it or point to alternatives like contacts.duplicates.check for likely duplicates or contacts.update for existing people.

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