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

With no annotations, the description carries the full burden and does well: it discloses result ordering (newest first), page size (~20), the 13-credit cost regardless of cache, and the refund policy on failure. It omits auth requirements and rate limits, but the pricing/refund/caching disclosures are genuinely valuable operational context.

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?

Roughly four tight clauses that are front-loaded with the core behavior (search semantics, ordering, page size) before moving to modes, use case, and pricing. No filler sentences; each clause adds distinct information.

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 4-parameter search tool with no output schema, the description covers ordering, page size, operator syntax, mode switching, and cost/refund behavior, which is enough to call it correctly. The `cursor`/`fresh` semantics live in the schema, so the description need not repeat them, though a note on result shape would round it out.

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 goes beyond it by showing concrete X search-operator syntax (`from:nasa`, `since:2026-09-01`, `lang:en`) usable inside `query`, which the schema only gestures at with "X's search operators." It also reinforces the post/user meaning of `type`.

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?

Specific verb+resource (search X, mirroring its own search box) plus scope qualifiers: newest-first ordering, ~20 per page, and the `type=user` switch for account search. An agent can tell this apart from get_x_posts/get_x_profile and from the other platform search_* siblings without opening the 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?

"Use this to follow a topic, a brand or a campaign" gives a concrete use context, and the `type=user` clause clarifies when to switch modes. No explicit when-not or named alternative sibling (e.g., vs get_x_posts for known accounts), so it stops short of a 5.

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