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

No annotations are provided, so the description carries the full burden. It does not say whether duplicate contacts are prevented, what happens if is_primary conflicts with an existing primary contact, whether the operation requires elevated permissions, or what the response contains.

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?

A single compact sentence with the verb and resource front-loaded and zero filler. It is efficient, though the brevity borders on under-specification for a six-parameter mutation.

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?

A mutation tool with no annotations, no output schema, and 0% parameter documentation leaves the agent without the behavioral or parameter detail needed to call it correctly. The description supplies role vocabulary but little else.

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 0% across six parameters. The parenthetical '(tenant, manager, billing, spouse)' gives useful meaning for the `role` field, but name, email, phone, is_primary, and customer_id are entirely undocumented in both schema and description.

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 and resource — 'Add a contact person to a customer' — which an agent can match to the intent of creating a new contact record. The parenthetical role examples add scope, though it does not explicitly distinguish itself from the existing sibling customers_contactUpdate.

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 guidance on when to use this versus customers_contactUpdate, nor any prerequisites such as the customer needing to exist or permission requirements. Only implied usage from the verb 'Add' and the role examples.

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