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

No annotations exist, so the description carries the full behavioral burden. It usefully discloses a cost of 1 credit, but says nothing about the return shape (holiday names, dates, locality scope), nor what happens when country or year are omitted even though both parameters are optional.

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?

One compact sentence with the core purpose front-loaded and the cost note trailing as a parenthetical. No wasted wording, though the credit note is slightly buried rather than integrated.

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 simple two-parameter lookup with no output schema, the definition covers the essentials but leaves notable gaps: default behavior when both optional parameters are omitted and a hint at the returned fields. Adequate but not complete.

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?

The description adds real value for `country` by giving ISO-code examples (GB, US, DE, FR) that the schema's bare 'string' does not. It adds nothing for `year`, whose accepted format (numeric 2024 vs. string) and default remain unclarified despite 100% nominal schema coverage.

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 the resource (public holidays) plus the two scoping inputs (country, year), which is enough for an agent to know exactly what it retrieves. Siblings (convert_time, fx_rates, time_now) are clearly unrelated, so no explicit differentiation is needed.

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 resource name; there is no explicit statement of when to call it versus another tool or of any prerequisites. Given the sibling set is disjoint (time conversion, FX rates, current time), the lack of exclusions costs little.

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