Get User Followers

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the description earns credit for adding what they cannot: API-key requirement, one request per call, ~1 unit cost with a per-result cost estimate, and the cursor-based pagination contract via completeness.nextCursor. Minor redundancy in restating "Read-only," which the annotations already declare.

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?

Front-loaded with purpose, then alternatives, then cost/behavior, then pagination — a logical progression with almost no filler. Slightly dense in the cost sentence and the redundant "Read-only" clause keep it from a 5.

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 3-parameter read tool with a full output schema and complete annotation coverage, everything an agent needs to call it correctly is present: identity input constraint, pagination loop, cost expectation, and sibling routing. Return-value detail is correctly deferred to the 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 coverage is 100%, so baseline is 3; the description still adds meaning by explaining that this variant fixes the page size (no count parameter exists here) and by spelling out the cursor round-trip using completeness.nextCursor from the prior result. This goes beyond the schema's per-field text.

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?

"Fetch one page of follower profiles for a user ID, at the default page size" states a specific verb, resource, and scope, and immediately contrasts itself with tweetapi_user_followers_list and tweetapi_user_followers_ids. An agent can distinguish this from the many other user_* siblings without opening a schema.

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?

Names two concrete alternatives and the exact condition that selects each (page-size control via count, IDs-only output). Combined with the schema's note about tweetapi_user_by_username for username inputs, the when-to-use and when-not-to-use routing is fully covered.

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