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

Annotations already declare destructiveHint=true, idempotentHint=true, and openWorldHint=true, so the safety profile is covered. The description adds the 'WRITE:' marker, the returned subscriber_id, and the underlying endpoint, but says nothing about whether the subscriber record is retained or whether the unsubscribe can be reversed.

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?

Three compact clauses with the write semantics front-loaded, the effect second, and the return value plus endpoint last. No filler sentences.

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 3-parameter tool with no output schema, the description usefully states what is returned (subscriber_id) and the scope of the effect. It falls just short of full completeness by omitting any note on permissions, error conditions, or what happens to the subscriber record after unsubscribing.

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 all three parameters (email, list_id, ip) are documented in the schema itself, including the ip default of 0.0.0.0. The description only implies list_id via 'from a list' and adds no format or constraint detail beyond the schema, so the baseline 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 ('unsubscribe') and resource (an email address) plus the effect scope ('from a list, so it no longer receives campaigns from that list'). It is easily separable from the sibling newsman_subscribe_email, though it never names the sibling explicitly.

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?

Usage is implied by the stated outcome: call this when a contact should stop receiving campaigns for a given list. There is no explicit when-not guidance, no prerequisites, and no mention of alternatives such as newsman_update_subscriber or newsman_remove_subscriber_from_segment for related operations.

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