Get User Highlights

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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds genuinely new operational facts: API key requirement, one TweetAPI request per call at roughly 1 unit, and a per-result cost estimate. It also flags the high-probability empty-result case, which prevents an agent from misreading an empty page as a failure.

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 what is fetched, then the empty-page caveat, then auth/cost, then pagination. Every sentence contributes an actionable fact and none restates the tool 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, return values need not be described, and the description covers the remaining unknowns: cost model, credential requirement, pagination protocol, and the common empty-result outcome. Nothing an agent needs to invoke this correctly 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 is 3, and the description goes further by spelling out the cursor round-trip ('call again with cursor set to this result's completeness.nextCursor'). The responseFormat and userId semantics are left entirely to the schema, which is acceptable given its completeness.

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 with scope: 'Fetch one page of the posts a user has added to the Highlights tab of their profile.' This is clearly distinguishable from siblings like tweetapi_user_tweets or tweetapi_user_photos, and 'one page' sets the retrieval boundary up front.

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 strong context for expectations (Highlights is an X Premium feature, so most accounts return an empty page) and explains the continuation loop via completeness.nextCursor. It does not explicitly name a sibling to use instead when Highlights is empty — e.g., tweetapi_user_tweets — so the alternative routing is left implicit.

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