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

Annotations only assert readOnlyHint and openWorldHint; the description adds real behavioral context beyond them — pagination contract (returns has_next_page + next_cursor, pass next_cursor as cursor) and credit cost model (13/tweet, 15 minimum, waived on bulk). This is meaningful disclosure the annotations do not carry.

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 cleanly sectioned into queryType, paging, and credits. Dense but every block earns its place; no filler or repetition.

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 complex search tool with no output schema and 0% param coverage, the description covers purpose, filter syntax, the two query modes, pagination, and cost. It stops short of describing result shape or rate/result limits, but the essentials for a correct call are present.

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 0%, so the description must carry the load, and it largely does: it enumerates the query operator syntax (from:, since:, min_faves:, filter:media, etc.), defines queryType's two values, and ties cursor to the returned next_cursor. Minor gap is no explicit format/limit notes on the cursor beyond re-use.

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+resource ('Search posts') scoped to 'full query syntax' with author/date/language/media/engagement operators. Clear what it does, but it never distinguishes itself from the sibling 'search' tool, leaving the agent to infer why the 'advanced' variant exists.

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?

Explains the queryType choice ('Latest' chronological default vs 'Top' engagement-ranked), which is useful routing. However it offers no explicit when-to-use-this-vs-alternatives guidance against siblings like search, user_search, or list_tweets_timeline.

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