x_search

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), and the description adds meaningful traits beyond them: per-post billing, a ~20-post page size, preserved Latest/Top ordering, retained reply/quote context, and the absence of automatic retries or popularity filters. Error-handling and rate-limit behavior beyond 'no retries' is left unstated, so not a full 5.

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 compact sentences, front-loaded with the purpose and return shape, each carrying distinct information (source, page size, ordering, billing, paging, retry policy). Slightly dense but no filler.

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 no output schema, the description correctly carries the return-value burden by describing page size, ordering preservation, and included reply/quote context. What remains thin is guidance on query construction and how cursor paging terminates, which a low-coverage schema does not cover.

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 only 25% (only 'detail' is documented), so the description must compensate and partly does: it explains ordering via the Latest/Top mention and paging via the cursor. However, it refers to 'next_cursor' while the actual parameter is named 'cursor', and it never characterizes the required 'query' parameter's syntax or the compact/full tradeoff.

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 ('Search X through TwitterAPI.io') and describes the return shape ('one whole upstream page... up to 20 posts'). An agent can immediately distinguish this from reddit_search and x_post without opening any 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 operational context ('Pass next_cursor to page') but never states when to choose this over reddit_search or x_post, nor any exclusions. Usage is implied by the resource name rather than explicitly routed.

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