calculate_date

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

With no annotations present, the description carries the burden of behavioral disclosure. It adds useful context by stating the tool is deterministic and correctly handles leap years and month-end edge cases. However, it does not mention return format, invalid-date handling, or timezone/calendar behavior, which are relevant for a tool with 9 parameters.

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?

The description is compact and front-loaded with the core purpose, followed by operation categories, a correctness guarantee, and a concrete example. Every sentence earns its place with no redundant content.

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?

Given the tool's complexity (9 parameters, 5 enums, no output schema), the description covers the main arithmetic and boundary operations but omits weekday operations, alternate calendars, and timezone handling. It does not describe the return shape, but the description is adequate for core usage without being fully comprehensive.

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 78%, which is high, so the baseline of 3 applies. The example '2026-01-31 + 1 month → 2026-02-28' clarifies the month-add semantics beyond the schema, but the description omits weekday operations (next_weekday/previous_weekday) and does not explain operation-specific parameter dependencies.

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 clearly states the tool performs deterministic date arithmetic, naming specific operation categories: add/subtract, snap to boundaries, and diff. It is distinct from the sibling tools' domains (time conversion, holidays, business days), but it does not explicitly name or contrast a sibling to help with disambiguation.

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 implies usage for general date arithmetic through its opening phrase and example. However, it provides no explicit guidance on when not to use this tool or which sibling might be more appropriate (e.g., business_days for business-day logic, convert_time for timezone conversion).

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