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 one meaningful behavioral nuance — that membership is based on the LAST mailing's hard bounce, not cumulative bounce history. It does not disclose pagination behavior or the member fields returned.

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?

Two front-loaded sentences with no filler; the defining condition precedes the endpoint path. 'GET /members/bounced' is mildly redundant given the tool name but cheap and useful for API-literate agents.

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 an all-optional, paginated read with no output schema, the description says what population is returned and what key field accompanies it. Missing only return-shape hints (e.g., which member fields appear) and a note that results are paged.

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%, including the unusual page guidance ('Pass the previous reply's next_page') and date-range semantics, so the schema does the heavy lifting. The description adds nothing about the seven parameters, which is acceptable at full coverage — baseline 3.

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 ('Members whose last mailing hard-bounced') and defines the qualifying condition precisely, including the returned datum ('with the bounce date'). This clearly separates it from cyberimpact_list_members and cyberimpact_list_unsubscribed_members.

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 '(invalid addresses to clean up)' implies the cleanup use case, which is useful context. However, it never states when to choose this over the sibling list tools (list_members, list_unsubscribed_members) or any exclusions such as soft bounces being absent.

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