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

With no annotations the description carries the full burden, and it does real work: it discloses the paid x402 requirement ($0.003 USDC on Base or Solana), the output shape, holiday scope, and the -260..260 business-day bound. It does not cover error behavior for invalid or out-of-range dates, which is the main remaining 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?

Front-loaded with the use case, then input rules, then output, then an example and price — a sensible information hierarchy with no filler sentences. The inline example URL is slightly cryptic (?start=... query-string form) and could be framed as a call example rather than a URL.

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 4-parameter tool with no output schema and no annotations, the description covers use case, input branching, output contents, holiday scope, limits, and cost — enough to call correctly on the first try. Only edge-case behavior (bad dates, holiday-fallback rules, response on missing country) is left unstated.

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 already 100%, so the baseline is 3, but the description adds value the schema lacks: it enumerates the valid country codes (KR, US, GB, DE, FR, JP) where the schema merely says "Public holiday calendar", and it surfaces the -260..260 range and the 2-year span limit. It stops short of format guidance for the date strings beyond what the schema states.

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 title and first sentence state a specific verb+resource pair (add or count business days) with two distinct operating modes, and the holiday-skipping scope separates it from plain date conversion (time_convert) or interval math (time_overlap). An agent can decide eligibility without opening the schema.

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 computing due dates, SLAs, settlement or delivery dates" gives concrete triggering contexts, and the description spells out the branching rule (give `days` to add, `end` to count, omit `country` for weekends only). What's missing is an explicit negative boundary, e.g. when to use time_convert or kr_public_holidays instead.

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