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

Adds real context beyond the readOnlyHint/openWorldHint annotations: it discloses that the live check performs exactly one handshake plus tools/list and calls no tools, which bounds side effects and latency. It also enumerates what the audit inspects (uptime, breaking changes, tool-list token cost), though it says nothing about rate limits, cost, or failure modes for unreachable URLs.

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 WHEN TO CALL trigger, then a dense but purposeful specification sentence. Slightly long-tailed in its audit-dimension list, but every clause carries information an agent needs to select and call it.

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?

Complete for a two-optional-parameter, read-only tool: triggers, inputs, live-vs-cached behaviour, and the shape of the output (0-100 plus prioritised fixes) are all covered without an output schema. Minor gap on error behaviour for bad serverId/url and on result turnaround.

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; the description earns an extra point by clarifying that serverId and url are alternatives ('Pass serverId ... or url') and by explaining the live-check semantics of url that the schema itself only hints at.

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 (audit an MCP server/repo/package/endpoint) and pins the deliverable: a 0-100 agent-readiness score plus prioritised fixes across named dimensions. The 'Lighthouse for MCP' framing plus the enumerated check list makes the tool's identity unmistakable.

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?

'WHEN TO CALL' gives explicit trigger conditions (building, debugging, configuring, comparing, evaluating a server/repo/package/URL). It does not, however, name or exclude any sibling — verify_tools, scan_tools, preflight_tools and check_tool_reliability all sit adjacent, and the description offers no guidance on when this audit beats those.

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