add_business_days

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

With no annotations, the description carries the full behavioral burden and meets it well. It discloses weekend/holiday skipping, the non-business-day start rule for both positive and negative N, and the fact that only the holiday list varies by country while the weekend definition is fixed.

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 compact and front-loaded, with the core operation in the first sentence and necessary edge cases following. Every sentence adds relevant information about the calculation, with no filler.

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 date-addition utility, the description covers the calculation logic fully and states that it returns the resulting date. The only minor gap is that it does not explicitly say the output is a YYYY-MM-DD string, which is otherwise implied by the input schema.

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%, giving a baseline of 3, but the description adds real parameter meaning beyond the schema: the subtle rule for start_date when it is not a business day and the clarification that country affects only the holiday list, not the weekend. This goes beyond the generic schema descriptions.

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 states a specific action and resource: 'Add N business days to a start date and return the resulting date,' with negative N explicitly allowed. This clearly distinguishes the tool from siblings like is_business_day or count_business_days, which perform different date operations.

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 usage is implied by the verb 'Add N business days' and the description of edge-case behavior, but it never explicitly names sibling tools or states when to use this tool instead of count_business_days or is_business_day. It provides clear context about how the tool behaves, but no explicit when/when-not guidance.

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