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

With no annotations, the description carries the full burden and handles it well: it discloses pricing ($0.25 USDC on base via x402), no-account/no-API-key/no-invoice access, the two-call payment flow, hourly rebuilds, and identical service to all buyers. This provides valuable behavioral context well beyond the schema.

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 four dense sentences with purpose front-loaded, followed by payment flow and fairness guarantees. Every sentence adds distinct information, with no filler or repetition.

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?

It covers the expected result, window behavior, and the important payment handshake in enough detail for an agent to call the tool correctly and interpret the response. Even without an output schema, the description's summary of 'services started/stopped with index-wide totals' is sufficient for a two-parameter tool.

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?

The input schema already covers both parameters fully: `days` is a 1-30 window defaulting to 7, and `payment` is an optional x402 header. The description mostly rephrases this and adds pricing/payment context, so the baseline of 3 is appropriate given 100% schema coverage.

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 identifies the tool's output as 'what came alive and what went dark' / 'services that started answering and services that stopped' across the whole index, with a configurable 1-30 day window. This is specific and sufficient to distinguish it from index-focused siblings like get_liveness_history or get_service_report.

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?

It gives explicit call guidance: omit `payment` to receive exact payment requirements, then call again with `payment` to be served. It also explains the configurable window, though it does not name sibling alternatives or state when not to use this tool.

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