country_rule

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

With no annotations, the description fully shoulders the burden. It discloses all key outputs (weekend day sources, calendar application, confidence, caveats) and implies read-only behavior. Missing are potential errors or auth requirements, but for a simple lookup, this is sufficient.

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: first lists what it returns, second gives usage advice. Front-loaded with 'USE THIS', no redundant words. Highly efficient and well-structured.

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?

Given the tool's simplicity (1 param, no output schema), the description is comprehensive. It covers what the tool does, what it returns, and when to use it. No gaps for an agent to make a correct decision.

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% with a clear description for the 'country' parameter (ISO 3166-1 alpha-2, examples). The description adds no additional parameter semantics beyond usage examples, so baseline 3 is appropriate.

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 clearly states that the tool inspects how bizdays treats a country, listing specific outputs (weekend days, sources, public holiday calendar, confidence flag, caveats). This distinguishes it from sibling tools that modify or calculate business days, so an agent can easily differentiate.

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?

Explicitly instructs to use this tool 'before relying on a result' and when a country is unusual (Gulf states, Israel, Nepal) or results are surprising. This provides clear when-to-use and implies when not to use, making it highly actionable.

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