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

Goes well beyond the annotations: clarifies that it 'lists, never calls a tool', that it detects OAuth/401 challenges (openWorld behavior made concrete), and explains the commercial model ($0.01/call via x402 USDC or card key, first 25 free, failed calls free). The note that 'each call is charged, so repeats are not free' directly explains the non-obvious idempotentHint=false, which annotations alone would leave ambiguous.

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?

The return contents are front-loaded and the pricing/usage notes follow logically, so an agent can stop reading early. It loses a point for redundancy: 'Read-only: it lists, never calls a tool' and 'Reads or computes only and changes nothing' say the same thing twice in one paragraph.

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 carries the return-value burden and does so by enumerating every field family returned. Combined with annotations covering safety and the explicit billing behavior, nothing an agent needs to call this correctly 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 coverage is 100% and the single parameter is already documented as 'The MCP server's streamable-HTTP URL'. The description adds a concrete example value (https://mcp.deepwiki.com/mcp), which clarifies the expected URL form beyond the schema's abstract wording.

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 ('MCP server check over streamable HTTP') and then enumerates exactly what is returned: initialize response, name, version, protocol version, capabilities, auth requirement, tool names/titles/descriptions/input parameters, and prompt/resource counts. This is precise enough to separate it from neighbors like openapi_summary or http_security_headers without opening a 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?

Gives explicit when-to-use contexts: 'vet an MCP server before adding it to an agent, or to check your own after a deploy', plus a concrete example invocation. It does not name a sibling alternative or state when not to use it, so it stops 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.