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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), and the description adds meaningful behavior: it may probe a live endpoint over the network, and the semantic prompt-injection pass requires a Pro API key sent as an Authorization: Bearer header. It doesn't mention rate limits, timeouts, or what happens on an unreachable server, so not a 5.

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?

Three sentences, purpose front-loaded, followed by input-mode guidance and an optional-capability caveat; little waste. It is fairly dense with parenthetical detail, but every clause contributes.

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, the description still conveys what the scan checks, which implicitly frames the report contents, and annotations carry the safety profile. It stops short of describing the actual response shape or failure behavior, which would matter for an agent acting on 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 coverage is 67%; the description adds real semantics on top of the schema by explaining the url vs. tools choice and the condition that selects the manifest path, plus the auth-header requirement tied to the Pro key. serverName is left unexplained, and the 'or' exclusivity between url and tools is only implied.

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 (scan/check) and resource (an MCP server) and enumerates exactly what it looks for: unauthenticated transport, capability overreach, known-bad signatures, plus optional prompt-injection detection. This clearly separates it from siblings scan_content, scan_extension and check_output, which don't target MCP servers.

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 a clear precondition ('before trusting it') and routes the two input modes explicitly: pass a live URL, or a manifest of tool definitions when the server isn't reachable over HTTP. It does not name sibling tools or state when not to use this one, so it falls short of a 5.

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