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

With no annotations, the description carries the full burden. It does add genuinely useful behavioral context that structured data lacks: the tool is paid ($0.005 per call) and the payment rail (USDC on Base). However, it stays silent on whether holidays are excluded, how invalid/reversed dates behave, and what the result looks like.

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?

A single sentence that front-loads the operation and appends the pricing detail in parentheses. Zero wasted words.

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 paid utility with no annotations, no output schema, and 0% parameter documentation, the description is too thin — date format, boundary inclusivity, holiday handling, and return type are all unaddressed.

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 0% — both 'from' and 'to' are untyped, undescribed properties. The description only says 'between two dates' and never specifies the accepted date format (ISO 8601, epoch, etc.) or whether the bounds are inclusive, so it fails to compensate for the coverage gap.

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 a specific verb (count) and resource (business days) plus the scope qualifier (between two dates, weekends excluded). This cleanly distinguishes it from sibling tk_describeDate, which operates on a single date rather than a range.

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?

No when-to-use, when-not-to-use, or alternative guidance is given. An agent can infer the purpose is a date-range computation, but nothing states prerequisites or when a sibling would be preferred.

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