calculate_date

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

The description discloses useful behavioral traits: determinism, UTC timezone, and business-day logic. With no annotations, the description carries the full burden, but it omits key behaviors such as output format, edge cases (invalid dates, negative amounts), and whether 'business_days' observes holidays.

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?

Single sentence, front-loaded with the core capability ('Deterministic ISO calendar math in UTC'), followed by an operation list. No wasted words, though the operation list is dense and could be formatted for clarity.

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 5-parameter tool with 0% schema coverage, no annotations, and no output schema, the description is inadequate: it fails to explain parameter usage, return values, or error behavior. It provides a high-level overview but leaves significant gaps an agent needs to call the tool correctly.

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%, so the description must compensate, yet it only loosely maps to parameters ('add days/weeks/months/years' hints at unit/amount, 'difference' hints at otherDate, 'weekday'/'business_days' map to operation). It does not explain how unit, amount, or otherDate interact, nor their defaults or constraints (e.g., amount limits, date format). Five parameters remain largely undocumented.

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 clear resource (ISO calendar math in UTC) and enumerates the specific operations: add days/weeks/months/years, date difference, weekday, business-day count. This lets an agent distinguish it from siblings like calculate_expression or convert_units. It's specific, though it doesn't explicitly name a sibling it should be preferred over.

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 enumerated operations imply when to use the tool (date arithmetic instead of general math), but there is no explicit when-to-use vs. alternatives guidance. With 12 sibling calculation tools, an agent could benefit from knowing this is date-only and cannot handle expressions.

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