Count trading days between two dates

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

With no annotations, the description carries full burden. It mentions inclusive range and exchange but does not disclose behavioral traits like return type, handling of invalid dates (e.g., start > end), or whether weekends are excluded. This is insufficient for a tool that modifies no state.

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 a single sentence with no redundant information. It is front-loaded and efficiently communicates the core functionality.

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 no output schema, the description should mention the return value type (presumably an integer). It also lacks details on edge cases and error handling. For a simple counting tool, it is moderately complete but has gaps.

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 description coverage is 67% (start and exchange have descriptions, end does not). The description adds that the range is inclusive and that exchange specifies the calendar, partially compensating for missing 'end' description. However, it does not provide extra meaning beyond the 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 verb 'count' and the resource 'trading days in the inclusive range [start, end] on an exchange.' It distinguishes from sibling tools like 'is_trading_day' and 'next_trading_day' by focusing on counting days between dates.

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?

There is no guidance on when to use this tool versus alternatives. No explicit 'when', 'when-not', or references to sibling tools are provided.

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