date

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

Annotations already declare readOnlyHint=true, but the description adds value by explicitly stating 'Read-only, no side effects' and describing the return format (JSON with ISO 8601 timestamp and timezone-aware fields).

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?

Four well-structured sentences that front-load the primary purpose, followed by safety, return type, and usage guidance. Every sentence is meaningful and concise.

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 5 parameters (0 required) and no output schema, the description covers purpose, usage, behavior, and return format. It references an alternative but doesn't detail parameter semantics (covered by schema). The overall completeness is high.

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 coverage is 100% and provides clear descriptions for all 5 parameters. The description mentions parsing a 'date string', but the schema only includes a numeric 'timestamp' parameter, causing slight inconsistency. The description adds little beyond the schema.

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's dual purpose: returning current system time or parsing a supplied date string as structured JSON. It uses specific verbs and resources, and distinguishes from the sibling 'uptime' tool.

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?

Explicit guidance on when to use (query system clock or validate date strings) and when not to (measuring elapsed time), with a direct reference to the alternative 'uptime' tool.

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