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

Goes well beyond the annotations: discloses the data sources (daily check of every remote server in the official MCP registry plus 30 days of history), the cost model ('paid per check'), the incentive for feedback (5 accepted reports earn 1 free call), and critically the safety boundary ('Reads the map only; never calls the server'). That last point strongly reinforces readOnlyHint/destructiveHint=false.

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-loads the when-to-use trigger, then the returned signals, then the local-server variant, then the cost/safety caveat. Dense and largely earned, though it is one run-on sentence with several stacked clauses that could be split.

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 enumerates the returned fields for both remote and local servers (up status, auth need, latency, tool risk breakdown, change recency, success probability, version, maintainers, install scripts), so an agent knows what it gets without calling. Nothing material 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 description coverage is 100%, so the server/last_trip/license_key semantics are already fully documented in the schema. The description only adds that checks are paid and points to list_paid_tools; it does not explain the last_trip report object or what a license key unlocks. Baseline 3 is appropriate.

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 states a specific verb and resource ('is it up, does it need sign-in...' about an MCP server before connecting) and even splits behavior by server type (remote registry server vs. local npm/PyPI package). It does not, however, differentiate itself from likely-overlapping siblings such as preflight or tool_card, so the agent must infer which check tool wins.

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 trigger ('before connecting to or calling any MCP server you have not used today, or before installing one that runs locally') which implies when not to use it, and routes pricing questions to list_paid_tools. No comparison against sibling preflight/tool_card, so the alternative-selection guidance is incomplete.

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