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

No annotations are provided, so the description carries full disclosure burden. It does not say whether matching is regex or literal, case-sensitive or not, whether non-matching lines are dropped, or what happens on no match. The '5 free trial calls per signed wallet' note gives payment context but no operational 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?

Front-loaded and short; the core behavior is stated in one clause. The trailing free-trial/emoji line is marginally useful payment context rather than padding.

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, zero-coverage tool with no annotations and no output schema, the description leaves the biggest risk unresolved: the text/input and search/pattern duplication. An agent has no stated basis for choosing among them, so required information 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?

Four parameters with 0% schema description coverage, and the description only vaguely maps to two of them ('pattern or search string'). Critically, the schema exposes two apparent synonyms for source text (text, input) and two for the query (search, pattern), and the description never disambiguates which to use or whether one overrides the other.

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: returning newline-separated lines of text that contain a given pattern. An agent can tell this is a line-filtering tool. It does not differentiate itself from near-neighbors like x402-line-contains or x402-find, but the purpose is unambiguous.

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?

No when-to-use/when-not guidance and no mention of alternatives in a catalogue containing many overlapping text-search tools. The only contextual note is a payment/trial-call line, which is not usage guidance.

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