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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint=false, so the safety profile is covered; the description goes further by disclosing a per-call price of $0.001 via x402, which is operationally important and appears nowhere in the structured fields. It also notes the relativity to a reference time and zone, which explains why results depend on when the call is made. Output details are left to the output 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?

Two sentences, front-loaded with the core verb and example inputs; the pricing note is appended as a distinct practical caveat. Nothing is repeated from the schema or annotations, and no sentence is wasted.

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 four-parameter, read-only resolution tool with an output schema, the description covers input forms, the anchoring semantics of reference/timezone, and the cost of invocation. The only meaningful omission is how genuinely ambiguous text (e.g. '3pm' with no date) behaves, though the forward_date parameter in the schema partially covers that.

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 75%, with only the required 'text' parameter lacking a description, and the description compensates by showing valid text forms such as 'in 2 weeks' and a date range. It also adds meaning to 'reference' and 'timezone' by framing them as the anchor against which the text is resolved, beyond the schema's terse default notes.

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 — 'Resolve natural-language dates ... to exact datetimes' — and backs it with three concrete input examples including a range ('Dec 25 to Jan 2'). This clearly separates it from siblings like date_add, date_diff, and timezone_convert, which operate on already-structured dates.

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 establishes the calling context ('relative to a reference time and time zone') and shows the shape of acceptable input, so an agent knows what to send. However, it offers no explicit when-not-to-use guidance and never routes the agent to a sibling — e.g. that date_add should be used for arithmetic on known dates rather than natural-language text.

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