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 useful paging behavior (page from 0, up to 1000 per page) and, importantly, the shape of each returned item (subscriber_id, email, status date) since there is no output schema. It says nothing about ordering of results or rate limits.

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 tight sentences, front-loaded with the core selection criteria before optional filtering, paging and item shape. The trailing 'GET /v2/list/getSubscribers' is marginal value for an agent but does not bloat the text.

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?

With no output schema, the description compensates by naming the fields of each returned subscriber, and it covers pagination and the date format semantics. Nothing crucial for correct invocation is missing, though result ordering would have closed the gap entirely.

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 coverage is 100%, so all five parameters are already documented, including the status enum and page/limit bounds. The description restates the status values, page origin and 1000-per-page cap, adding no format or behavioral detail beyond the schema—correct 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 (list), resource (subscribers of a list), and the discriminating axis (status enum plus optional join date). It implicitly separates itself from siblings like newsman_count_list_subscribers and newsman_list_segment_subscribers, but never names those alternatives 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?

The description explains the optional 'since' filter (joined on or after a UTC date), which implies when to use it. It gives no explicit guidance on when to pick this tool instead of count_list_subscribers, search_subscribers, or list_segment_subscribers, leaving selection logic to inference.

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