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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds a genuinely non-obvious downstream rule - these contacts must never be re-mailed - which changes how an agent should act on the result. It omits anything about pagination behavior or response size, keeping it below a 5.

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 short sentences, front-loaded with the resource and scope; nothing is padded. The trailing 'GET /members/unsubscribed' restates implementation detail an agent cannot act on, a minor waste.

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 7-parameter, zero-required list tool with no output schema, the description covers what the records are and one returned field (unsubscribe date). It does not convey the shape of the response or that results are paginated, which the agent must infer from the page/limit schema.

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%, with all seven parameters (page, limit, sort, and the updatedOn/unsubscribedOn date bounds) fully documented including formats and defaults. The description adds no parameter detail beyond the schema, 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 the specific resource (members who unsubscribed) and the key attribute carried (the unsubscribe date), which distinguishes it from the sibling list_members and list_bounced_members by name alone. It never explicitly says 'list' or names the sibling alternatives, 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?

Usage is implied by the resource itself, and 'These contacts must not be mailed again' signals the compliance/audit use case. However, it gives no explicit guidance on when to pick this over list_members, list_bounced_members, or get_member, and states no exclusions or prerequisites.

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