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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds that resolution is timezone-scoped, but says nothing about how ambiguous or unparseable expressions are handled, nor what form the resolved value takes (timestamp, ISO string, object). With annotations doing the heavy lifting, a 3 fits.

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?

A single well-formed sentence with the examples front-loaded; nothing is wasted. It is arguably too terse for a tool whose output format matters, but there is 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?

No output schema exists, so the description should say what a 'resolved' expression looks like and in what format, which it does not. Three params with one entirely unaddressed (country) and no error/ambiguity behavior leaves real gaps, though the core call is inferable.

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 67%, so tz and country are documented in the schema; the description only reinforces tz ('in a timezone'). The country parameter — which selects business-day holiday calendars — is not mentioned at all in the description, and expr has no schema description either, so the description adds little beyond the schema.

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?

States a specific verb (resolve) and resource (relative time expression) and grounds it with three concrete example inputs, plus the timezone scoping. It does not distinguish itself from siblings like add_business_days or convert, which also manipulate dates, so an agent must infer the boundary.

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?

Usage is only implied by the example expressions; there is no explicit statement of when to choose this over add_business_days (which also handles 'business days') or convert. The 'in 2 business days' example actually overlaps a sibling's apparent domain without saying which to prefer.

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