Get Following IDs

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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, yet the description still adds real value: API key requirement, one TweetAPI request per call, roughly 1 unit of cost, and a cost estimate in each response. It does not mention rate limits or throttling behavior, so it is strong but not complete on the operational side.

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 tight sentences, front-loaded with what is returned and the cheapest-use case, then cost, then pagination. No redundant restatement of the name or title; every clause carries a distinct fact.

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 paginated, cost-metered read tool with an output schema, the description covers the payload shape, cost model, auth need, and the exact continuation loop. Nothing an agent needs in order to call it correctly and iterate pages is missing.

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 would be 3, but the description goes beyond the schema by tying the cursor parameter to a specific output field ('this result's completeness.nextCursor'), which tells the agent where the next value comes from. The count parameter is left to the schema, which is acceptable at full coverage.

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 — fetch one page of user IDs that a given user ID follows — and immediately scopes the payload as 'strings only, no profiles', which is exactly what separates it from the profile-returning following-list siblings. An agent can pick this tool without opening the 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?

Gives a clear selection cue ('cheapest way to walk a large following graph') and a concrete pagination procedure, plus the schema note routing username-only callers to tweetapi_user_by_username. It stops short of naming the alternative explicitly (e.g. 'use tweetapi_user_following_list when you need profiles'), so the when-not guidance is implied rather than stated.

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