Verify an endpoint

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

Goes well beyond the annotations: no account is required (auth context), an unseen URL is queued for a crawl and returns HTTP 202 with a retry-after-a-minute instruction, and the response contents are described. The asynchronous, non-idempotent nature is explained in a way that explains the idempotentHint=false annotation rather than merely repeating it.

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 with the purpose and the key differentiator, then usage, then the 202 edge case. Dense but each clause carries information; the em-dash middle clause is slightly crowded but not wasteful.

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?

No output schema exists, so the description carries the return-value burden and does so ('Returns JSON with the listing, the signals found and when it was last looked at'). The async 202 retry path covers the main source of agent confusion for a single-param verification tool.

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 URI parameter is already documented. The description still adds meaning by naming the acceptable URL families (MCP, A2A, x402) and clarifying that it accepts an endpoint or origin, which the generic 'uri' format does not convey.

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?

Names a specific verb (checks/verifies) and resource (an MCP, A2A or x402 URL) and enumerates exactly what it inspects: reachability, what it demands, card changes, and prompt-injection signals. It explicitly separates itself from search_agents, so an agent can route correctly without opening either 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?

States the trigger condition (you have a URL from elsewhere) and the alternative for the contrasting case (for a need rather than a URL use search_agents). It also defines a follow-up protocol for unknown URLs, so the agent knows both when and how to use it.

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