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

No annotations are provided, so the description carries the behavioral burden, and it discloses the non-obvious traits: this is a paid call ($0.001 via x402, USDC Base) and returns ISO-8601 UTC with unix seconds. It does not state whether the charge applies per call or what happens on payment failure, leaving a small gap.

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?

Two compact sentences: cost first (the most decision-relevant fact for an agent paying per call), then return format, then positioning against alternatives. No filler.

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?

For a zero-parameter tool with no output schema, the description supplies everything needed: the price/mechanism of access, the exact return format, and the intended use case. Nothing required to call it 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?

The tool takes zero parameters, which sets the baseline at 4 per the rubric. There is nothing further the description could meaningfully add about inputs.

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?

Names a specific verb+resource (get_time) and immediately specifies the payload: current server time in UTC ISO-8601 plus unix seconds. The trailing 'cheapest liveness/time probe' distinguishes it from other status-style siblings like reactor_status.

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?

'Cheapest liveness/time probe' gives a clear usage context (liveness checks, time retrieval) and implicitly ranks it against alternative probes via 'cheapest'. It stops short of an explicit 'when not to use' or naming the alternative tool, so it is clear context rather than full routing guidance.

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