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

Annotations already declare destructiveHint=true, idempotentHint=true, and readOnlyHint=false; the description earns extra credit by naming the blast radius ('the subscriber stays on the list'), which tells the agent exactly what is and is not destroyed. It does not mention failure modes or return payload, but that is a minor gap given the annotation coverage.

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, front-loaded with 'WRITE:' so the mutation nature is immediately visible, followed by the clarifying parenthetical and endpoint. Nothing is wasted.

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 two-parameter write with full schema coverage and no output schema, the description covers purpose, mutation type, and scope caveat adequately. Only the no-output expectation and any permission requirements are left unstated, which is a small gap.

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% and both parameters are documented as 'NewsMAN subscriber id' and 'NewsMAN segment id'. The description adds no syntax, format, or accepted-value detail beyond that, so the baseline of 3 applies.

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 ('remove a subscriber from a segment') and adds the crucial scope clarification that the subscriber remains on the list, which cleanly separates it from unsubscribe_email and the add_to_segment sibling. The endpoint path reinforces the exact operation.

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 parenthetical '(the subscriber stays on the list)' implies the contrast with unsubscribe_email by clarifying this is a segment-scoped removal, but there is no explicit statement of when to choose this tool versus unsubscribe_email or add_subscriber_to_segment. Usage is inferable but not spelled out.

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