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

With no meaningful annotations (all hints false), the description carries the transparency burden and does a good job: it discloses inclusivity, the presence of weekend/holiday counts, and the critical 'no holiday calendar' behavior. It does not describe the exact return structure, but the output components are named.

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?

Two sentences with no filler. The main purpose is front-loaded, and the crucial no-holiday-calendar caveat is placed immediately after, making the most important limitation easy to notice.

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 moderate-complexity calculation tool with full schema parameter descriptions, the description is largely complete: it states purpose, inclusivity, result components, and the holiday limitation. It does not spell out the exact return format or behavior for edge cases like from > to, but those are not essential for correct invocation.

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 100%, so the schema already documents all four parameters. The description adds context like 'inclusive' and the weekend/holiday-count behavior, but it mostly reinforces the schema rather than adding new parameter-level meaning.

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 names a specific action (count), a specific resource (business days between two dates), and the scope (in a place, inclusive). It also states what the result includes (calendar total, weekend count, holiday count), which clearly distinguishes it from sibling time/calendar tools like convert_time or dst_changes.

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 gives clear context for when the tool is appropriate and explicitly warns that the result is not holiday-adjusted unless holidays are passed. It does not name sibling alternatives or give an explicit 'use X instead' rule, but the limitation is stated strongly enough to prevent misuse.

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