date_math

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the operation and units but does not mention return format, timezone handling, or edge cases like invalid dates. For a calculation tool, this leaves important behavioral aspects undisclosed.

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 a single concise sentence that front-loads the core operation. It wastes no words and is easy to parse quickly.

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?

The tool has a nested object and no output schema, so the description should explain the return value or typical use cases. It only covers the operation, leaving the agent uncertain about what the tool returns (e.g., an ISO string) and how it handles edge cases. For a moderately complex tool with no annotations, this is incomplete.

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?

The input schema already describes both parameters with 100% coverage, including the date format and the add object's negative-value behavior. The description's enumeration of units adds minimal value beyond the schema, so the baseline score of 3 is appropriate.

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 uses a specific verb ('add or subtract') and resource ('time from a date'), and enumerates the supported units. This clearly distinguishes it from sibling tools like date_diff (which computes differences) and format_date (which formats dates).

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 date offset calculations but does not explicitly state when to use this tool versus alternatives like date_diff or business_days. No exclusions or alternative tool references are provided, so the guidance remains implicit.

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