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

With no annotations, the description carries the full burden and does well: it discloses the returned fields (including DST-active flag and standard offset to distinguish a shifted clock from a permanent one) and, unusually, the cost and payment mechanism ($0.005/call over x402 USDC). It omits error behavior for invalid zone strings and any latency expectation.

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?

Three sentences, front-loaded with the 'Use when' trigger, and the output enumeration is informative rather than filler. The pricing sentence sits slightly apart from the functional narrative but still earns its place.

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 must — and does — enumerate the return values, including DST state and standard offset. Combined with the cost disclosure, an agent knows what it gets and what it pays; only failure modes for bad zone input are unaddressed.

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?

There is a single parameter with 100% schema description coverage that already specifies IANA format and requiredness. The description says 'in a particular place' but adds no format, casing, or rejection guidance beyond the schema, so the baseline 3 applies.

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 makes clear this returns the current time in a place, and enumerates the exact output forms (ISO with offset, 24-hour, 12-hour, weekday, unix, UTC) plus DST status and standard offset. It never names the obvious siblings time_convert or time_zones, so the boundary between this and those is left to inference.

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?

'Use when an agent must stamp or schedule something in a particular place and needs every form at once' gives a concrete triggering condition. However, there is no explicit when-not or pointer to time_convert/time_zones for agents that only need one format or a cross-zone conversion.

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