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

With no annotations, the description carries the full burden and does so: it discloses the side-effect profile ('No credential is sent, none is obtained, and none of their tools is ever called'), reports statefulness via Mcp-Session-Id, distinguishes refusal bodies, and explains the RFC 9728 resource_metadata resolution it performs. This is unusually rich behavioral context for a probe 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?

Front-loaded with the core verb and outcome, and every clause adds actionable detail (verdict taxonomy, credential-safety guarantee, RFC 9728 pointer behavior). It is dense and slightly overlong, but few sentences are expendable.

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?

There is no output schema, so the description must describe return values, and it does: it enumerates the verdict set, refusal body shape, statefulness, tool count, and authorization-server discovery. Coupled with a 100%-covered input schema, an agent has enough to call and interpret the tool correctly.

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 baseline is 3, but the description adds meaning beyond the schema: it explains that `urls` checks a whole mcp.json in one call, is capped at 5, and shares a daily egress budget. It does not, however, clarify how `url` and `urls` interact or whether both may be supplied.

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 (run the MCP handshake against any https endpoint) and enumerates the precise outputs it returns (verdict values, statefulness, tool count, guard clauses). This is clearly separable from siblings like verify_surface or get_surface_contract, which concern surfacing contracts rather than live endpoint preflight.

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?

Gives an explicit use condition: 'Use it before wiring an MCP server into your own config.' This frames the when-to-use well, but it names no alternative tool or exclusion, leaving the agent to infer when verification/preflight is not appropriate.

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