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

No annotations exist, so the description carries the full burden. It does disclose the genuinely non-obvious behaviour, the x402 payment model at 0.002 USDC per call, and the paymentProof description supplies the 402-handshake flow. It says nothing about side effects, rate limits, or what the response looks like, which leaves meaningful gaps for an unannotated tool.

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, front-loaded with the core function and followed by the pricing constraint. Nothing is redundant and every clause carries information an agent needs.

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?

With no output schema and no annotations, the description should at least indicate the return type, and it is ambiguous whether counting returns an integer while adding returns a date. The payment and holiday-skipping semantics are covered, but the return contract is not.

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 80%, so the baseline is 3. The description adds the useful fact that 'add N business days' corresponds to the undocumented add parameter, but it does not clarify the required from plus to combination for counting mode, or what happens if both to and add are supplied.

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 computation (count working days, or add N business days to a date) and its defining rule (skip weekends and official public holidays for a given country), which clearly distinguishes it from the neighbouring date_diff and public_holidays tools without naming them. It is not a tautology, but it never explicitly routes against those siblings.

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?

Two distinct modes are announced, but the description never states which parameter selects which mode (to for counting vs add for shifting), nor when an agent should prefer this tool over date_diff or public_holidays. Usage is implied by the prose rather than operationalized.

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