Semantic search over the x402 catalog

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

No annotations are supplied, so the description carries the full behavioral burden. It does disclose a meaningful trait beyond the schema — the tool is non-evaluative ('no verdicts') and semantic rather than substring-based — but says nothing about authentication needs, rate limits, pagination, or result shape. Useful context, yet insufficient for an annotation-free tool.

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?

Two tight sentences with zero filler; the core purpose is front-loaded and the scope qualifier follows immediately. Every phrase earns its place.

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 simple two-parameter search with no output schema, the description covers the intent and the semantic-matching behavior but omits anything about the returned result (e.g., what a match contains or whether relevance scores are included). Adequate but leaves the agent guessing about output shape.

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 100%, so both the query and limit parameters are already fully documented, including the 'matching is by meaning, not substrings' note. The description repeats that same semantic-matching idea without adding formatting or syntax meaning beyond the schema, making the baseline 3 appropriate.

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 ('Meaning-based search across the catalog') and clarifies the input style ('describe the capability you need in plain words'), which is more precise than a generic 'search the catalog'. However, it never distinguishes itself from the closest sibling, x402_search, so the agent cannot tell the two apart without inspecting both schemas.

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?

'Discovery only, no verdicts' gives a clear scope boundary that implicitly routes evaluation-type queries to the trust siblings (x402_trust_score, x402_trust_preview). It does not explicitly name an alternative or state when to prefer x402_search over this tool, so it stops just short of full routing guidance.

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