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

No annotations are provided, so the description carries the full burden, yet it reveals only that two day-counting modes exist. It says nothing about whether this is a pure computation, what the returned value looks like, whether the result skips weekends or holidays, or that an access_token is required for a PRO-tier call.

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?

It is a single short sentence with no padding, so it is front-loaded and cheap to read. The 'PRO.' prefix is unexplained noise, and concision here reads more like under-specification than discipline.

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?

A four-parameter tool with no annotations and no output schema needs the description to cover mode values, date format, return shape, and auth. None of that is present, so an agent cannot call this confidently without inspecting sibling tools.

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 only 25% — only access_token is documented — so start, days, and mode rely on description text. The description maps loosely onto start/days and hints that mode selects calendar vs. business days, but it never states the accepted mode values or the expected date format for start, so half the semantics remain guesswork.

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 concrete computation (due date = start + N days) and the two modes that govern it, which is enough to know what the tool returns. It does not, however, distinguish it from the sibling business_days, which appears to be the obvious alternative for the business-day case.

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 pick this over business_days or next_holidays, and no statement about how holidays interact with the business-day count. The only implied routing signal is the vague 'calendar or business days' phrasing, which is left for the agent to interpret.

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