list_holidays

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

With no annotations, the description fully covers behavioral aspects: sorted output, inclusion of weekend holidays, case-insensitive country normalization, case-sensitive subdiv, unsupported category filtering, and error conditions (ValueError). This exceeds minimal disclosure.

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?

The description is well-structured with clear sections for arguments, return value, and errors. Every sentence adds meaningful information without redundancy. It is appropriately sized for the tool's complexity.

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?

The description covers all aspects: input constraints, output structure, error handling, and behavioral notes. Given the output schema exists, the description still explains the return format, ensuring completeness. No gaps remain for this 3-parameter tool.

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 0%, so the description must compensate. It explains each parameter in detail: year format, country code case-insensitivity and normalization, subdiv optionality with examples and limitations, and provides concrete example ('country=DE, subdiv=BY'). This adds significant value beyond the raw schema.

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 the tool's purpose: listing all holidays for a given year and country, sorted by date. It uses a specific verb ('list') and resource ('holidays'), and distinguishes from sibling tools like 'business_days_between' and 'is_business_day' by focusing on full holiday enumeration.

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 provides explicit usage scenarios ('for display, planning, or cross-referencing') and mentions that holidays on weekends are included. It does not explicitly state when not to use or name alternatives, but the context is clear enough for an agent to decide.

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