holidays

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

With no annotations, the description carries the full burden and does well: it discloses cost ($0.003 USDC per call), p99 latency (300ms), geographic coverage, and default values for year and include_observances. It omits auth requirements and return shape, 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?

Front-loaded with the core capability, then a compact parameter digest. The param list partly restates the schema, but the examples earn their place; nothing is padded.

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 6-param read-only lookup with no output schema, the definition covers scope, modes, examples, cost and latency. The only gap is the shape of the returned holiday records, which the agent must discover empirically.

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%, and the description supplements it with concrete examples for country (DE, US, CH, JP), region (BY, CA, ZH), language (en) and date format (YYYY-MM-DD), plus explicit default semantics. It adds real value beyond the bare schema types.

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?

Names a specific resource (public/bank holidays) with scope (200+ countries and their regions, any year) and a secondary capability (check a date). No sibling in the list overlaps, so the agent can select it unambiguously.

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?

The description makes the two usage modes explicit: bulk listing by country/region/year, and 'optionally check whether a given date is a holiday.' It doesn't state when NOT to use it or name alternatives, but the tool is unique among siblings so that omission costs little.

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