Get User Tweets And Replies

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

Goes well past the annotations by disclosing the auth requirement (TweetAPI API key), the cost model (one request per call, usually 1 unit, with a per-result cost estimate), and the pagination contract including the exact next-cursor field. The annotations already cover safety and idempotency, so this is genuinely additive context about billing and paging behavior.

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 the tool returns and immediately followed by the disambiguating alternative. Every sentence carries distinct information: scope, sibling routing, cost, and pagination — no filler or restatement of the title.

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?

With an output schema present, the description needn't explain return shapes, and it still flags that each result carries a cost estimate and a completeness.nextCursor. Auth, billing, paging, and sibling disambiguation are all covered, leaving nothing an agent needs before calling it.

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% and both the cursor and userId semantics (numeric-only, no username lookup) are already documented in the schema. The description restates the cursor round-trip rather than adding new parameter-level detail such as how responseFormat affects fields; baseline 3 applies when the schema does the heavy lifting.

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 a user's posts including their replies") plus a concrete mental model ("as on the Replies tab of their profile") that makes the scope unambiguous. It then names the sibling it is not (tweetapi_user_tweets for original posts only), so an agent can choose between the two 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?

Explicitly routes to the alternative: use tweetapi_user_tweets for original posts without replies, implying this tool is for posts-plus-replies. The schema description further routes username-only callers to tweetapi_user_by_username first, so the prerequisite and exclusion conditions are both covered.

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