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

The description discloses that this is a real live network operation (not simulated), performs a JSON-RPC handshake and tools/list, and is deterministic with no LLM. This adds behavioral context beyond the readOnlyHint annotation, including what the tool returns and that it makes an actual remote call.

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 description is three sentences, front-loaded with the core purpose, followed by specific output details and a concrete use case. No word wasted; each sentence earns its place. It is appropriately sized for a tool with one parameter.

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?

The description covers what the tool does, what it returns (status, protocol version, server name/version, inventory, transport, latency), and its deterministic nature. Since there is no output schema, the description fully compensates by listing the return fields. For a single-parameter tool, this is complete.

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% with a clear parameter description for 'url'. The description simply restates 'by URL' without adding new constraints or format details. The schema already tells the agent the parameter is an endpoint URL, so the description adds marginal value beyond that.

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 clearly states the specific verb+resource: health-check a live MCP server by URL. It details the exact operations (initialize handshake, tools/list) and distinguishes itself from sibling tools focused on agent readiness or domain health by targeting MCP protocol compliance specifically.

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 explicitly states when to use it: 'Use it to verify your own MCP server is alive and spec-compliant.' It does not name alternatives or exclusions, but the use case is clearly scoped. Sibling tools exist for other health checks, so this gives adequate guidance without listing when-not conditions.

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