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

With no annotations provided, the description carries the full burden of behavioral disclosure, and it does well by stating that the operation is public, requires no key, and returns specific fields (tools, network, payTo, per-tool price in sats). It implies a read-only listing operation, though it does not explicitly mention pagination or rate limits.

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 deliver the core purpose, auth requirement, and return fields with no filler. The most important distinguishing facts (public, no key, registry listing) are front-loaded, and every clause adds value.

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 optional-parameter listing tool with no output schema, the description is complete: it states the purpose, auth requirements, and the key return fields. The remaining details (q and limit semantics) are adequately covered by the input schema, and no critical invocation detail 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?

Schema description coverage is only 50%, with 'limit' lacking any description and 'q' having only 'Search text'. The tool description adds no parameter-level meaning, so it does not compensate for the schema's gaps. The parameters are not mentioned at all, leaving the agent to infer their purpose from minimal schema hints.

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?

The description uses a specific verb ('Browse') with a clear resource ('x402market registry of pay-per-call services'), which distinguishes it from sibling tools like pay_service, service_quote, and list_transactions. It also states the audience ('for agents') and the public nature of the operation.

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 clearly conveys that this is a public registry-browsing operation and that no key is needed, giving an agent a clear context for when to call it. It does not explicitly name alternatives or state when not to use it, but the discovery-focused framing is strong enough to imply the appropriate use case.

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