Get User Tweets

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

Annotations already declare readOnly/idempotent/non-destructive, and the description still adds real context beyond them: an API key is required, each call makes exactly one TweetAPI request usually costing 1 unit, and results carry a cost estimate. It also discloses the page-at-a-time return shape, which annotations cannot express.

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 purpose and scope, then alternative, then cost/auth, then pagination. No filler and nothing repeated from the schema verbatim.

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, metered read tool this covers everything an agent needs to decide and invoke: scope, sibling alternative, auth, cost model, and the pagination loop. Return-value detail is legitimately omitted because an output schema exists.

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, but the description adds the cross-field relationship the schema cannot: the cursor value comes from the prior result's completeness.nextCursor. It doesn't elaborate on userId format or responseFormat trade-offs, but those are fully covered 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?

"Fetch one page of a user's original tweets, without replies" names the verb, the resource, and the scope exclusion in one clause. It also names the exact sibling that covers the adjacent case, so an agent can distinguish it from tweetapi_user_tweets_and_replies without opening either 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?

Explicit routing: use this tool for original tweets, use tweetapi_user_tweets_and_replies to include replies. Pagination guidance is also actionable ("to get the next one, call again with cursor set to this result's completeness.nextCursor"), leaving no inference needed.

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