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

No annotations are provided, so the description carries the full behavioral burden. It states the operation and input format, but does not disclose whether negative durations are allowed, how timezones are handled, what happens on invalid input, or what the result looks like.

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 efficient sentence that front-loads the operation and the input format. Every word earns its place with no redundant or filler 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?

For a tool with a nested payload, no annotations, and no output schema, the description is too thin. It omits return value expectations, timezone behavior, and duration sign semantics, leaving meaningful gaps for correct invocation.

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%, and the description partially compensates by naming all duration units and the ISO 8601 datetime input. However, it does not clarify the nested payload wrapper, required datetime field, default values, integer typing, or whether values may be negative.

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 states a specific verb, resource, and target format: add a fixed duration to an ISO 8601 datetime. It is clear what the tool does and distinguishable from generic time utilities, though it does not explicitly route against siblings like time_between or time_convert.

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 explicit when-to-use guidance, no prerequisites, and no comparison to alternative time tools. The implied use case is obvious from the action, but the description does not help an agent choose this tool over time_parse, time_format, or time_between.

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