datetime_now

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

The description indicates it returns the current datetime, which is inherently non-destructive. However, no annotations exist, and the description does not confirm safety or lack of side effects, which is acceptable but minimal.

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 one sentence, concise and front-loaded with a tag, containing no extraneous information.

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 an output schema, so return format is covered, but the description omits explanation of the timezone parameter, leaving a significant gap for a simple tool.

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 single parameter 'timezone' is not explained in the description; schema-coverage is 0% with no descriptions. The agent has no guidance on how to use or omit it.

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 'Return the current date and time as ISO 8601', providing a specific verb and resource, and distinguishes from sibling datetime tools that perform other operations.

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 gives no explicit guidance on when to use this tool versus alternatives, nor any when-not-to-use conditions. It implicitly serves as a simple clock, but lacks usage context.

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