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

With no annotations, the description carries the full burden and does disclose real behavioral traits: the return fields (offset, abbreviation, local time, DST state) and the payment model ($0.005/call over x402 USDC). It omits rate limits, error/pagination behavior, and how often offsets refresh, so it falls short of a 5.

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, zero filler, and front-loaded with the core capability and the returned data before the usage hint and pricing. Every sentence 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?

There is no output schema, so the description must explain returns — and it enumerates them precisely. Combined with the usage framing and cost disclosure, an agent has everything needed to select and invoke this tool correctly.

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 100%, so the baseline is 3. The description restates the offset-filter use case ('find every zone sitting at a given offset right now') and implies the search-into-zone-name flow, but adds no format or syntax detail beyond what the schema already provides.

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 and resource ('Search the full IANA time zone list') and immediately enumerates the returned fields (UTC offset, abbreviation, local time, DST state). This cleanly separates it from siblings like time_now and time_convert, which operate on an already-known zone.

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?

Gives two concrete use cases: mapping a city/country to a zone name other endpoints expect, or finding zones at a given offset. It references the sibling endpoints implicitly, but does not state exclusions or when a sibling like time_convert is the better call instead.

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