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

Annotations already cover read-only/idempotent safety, and the description adds genuinely useful context beyond them: default 20 / max 100 page size, signed snapshot cursors valid 24 hours, and that hiding and suppression still apply to old cursors. 'Never signs payments' also preempts a plausible agent misread of an x402 listing search. It stops short of describing return shape or error 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?

Compact and front-loaded: facet list first, then paging/cursor rules, then trust caveats, then the safety disclaimer. Every clause carries information and none is redundant 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 and nine parameters at 0% schema coverage, the description does well on inputs but says nothing about what a listing result contains, how pagination terminates, or empty-result behavior. Adequate for invoking the tool, thin for interpreting its results.

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 carries the full burden, and it does reference all nine parameters (text, host, category, grade, owner_verified, featured, sort, limit, cursor) while adding semantics the schema lacks, such as cursor lifetime and sort options. It still omits matching syntax for `text`/`host` and the meaning of filtering on an absent value.

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 (search) and resource (scanned x402 services) and enumerates the filterable facets, so the purpose is unambiguous. However, it never distinguishes this tool from the near-identical sibling `search_services` (or `retrieve_listing`/`get_service`), so an agent cannot choose between them from the description alone.

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?

The description implies usage through its filter list but gives no explicit when-to-use, when-not-to-use, or alternative routing, which is a real gap given that `search_services` and `export_listings` sit right beside it. The only constraint offered is the behavioral note that it never signs payments.

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