Get Follower IDs

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

The 'Read-only' claim is consistent with readOnlyHint=true and destructiveHint=false, so no contradiction. Beyond the annotations it adds real context: API key required, one request per call, roughly 1 unit of cost with a cost estimate in each result, and a page-by-page continuation model. That is useful, but return-shape detail is largely delegated to the output schema.

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?

Four short sentences with no filler: what it returns, why to pick it, cost/auth profile, and how to paginate. The payload constraint and the cheapness claim are front-loaded where an agent will read them first.

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 three-parameter paginated read with a full output schema, everything an agent needs is present: auth requirement, cost model, single-request semantics, and the next-page procedure. Return values correctly are not duplicated in prose because the output schema covers them.

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 the baseline is 3, and the description adds the paging contract by tying the input cursor to this result's completeness.nextCursor, making the loop explicit. It says nothing about the count ceiling or the username-lookup prerequisite, both of which live only in the schema.

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 concrete verb and resource (fetch follower user IDs for a user ID) and immediately delimits the payload as 'strings only, no profiles', which separates it from the profile-returning followers siblings. It does not name any sibling tool explicitly, so the differentiation is inferential rather than stated.

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?

'Cheapest way to walk a large follower graph' gives a clear selection criterion and the pagination instruction explains the continuation loop. It stops short of an explicit exclusion such as 'use tweetapi_user_followers_list when you need profiles', leaving the agent to infer the alternative from what is absent.

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