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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context: pagination behavior (20 per page, cursor-paginated) and the return shape (full user objects under `followers`). It does not mention rate limits or error cases, but the added pagination and response structure details go beyond the annotations.

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 sentences with no wasted words. The core purpose and pagination detail are front-loaded, followed by use-case context and a clear pointer to the sibling tool. Every sentence earns its place.

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?

The description is complete for a read-only, cursor-paginated list tool. It explains the return structure (full user objects under `followers`), pagination, and the distinction from the sibling tool. The output schema exists, so return values are further documented. Minor gaps like rate limits or error handling are not critical given the annotations and output 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%, so the schema already documents both parameters (list_id and cursor). The description adds context about cursor-paginated usage but does not provide additional parameter-level detail beyond what the schema offers. Baseline 3 is appropriate since the schema carries the parameter documentation burden.

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?

The description clearly states the tool lists accounts subscribing to an X List, with pagination details (20 per page, cursor-paginated). It explicitly distinguishes itself from get_twitter_list_members, which lists accounts included in the List, not subscribers. This makes the purpose unambiguous and differentiates it from the closest sibling.

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 provides explicit usage context: use it to gauge attention a curated list attracts and who cares about the topic. It also names the alternative tool (get_twitter_list_members) and the condition for choosing it (when you need accounts included in the List, not subscribers). This is clear when-to-use and when-not-to-use guidance.

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