date_info

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

No annotations are provided, so the description carries the full burden. It lists the type of information returned but does not disclose behavior for 'now', timezone assumptions, error handling for invalid dates, or that it is a read-only operation. The list of outputs is helpful but under-specified.

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 sentence that starts with the verb and resource, followed by examples of the returned data. Every word is substantive; there's no filler.

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 simple one-parameter tool, the description covers the main purpose and sample outputs, but 'and more' is vague and there is no mention of timezone handling or the structure of the response. Since there is no output schema, the description could be more explicit about the return format, but it is largely adequate.

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 documents the single 'date' parameter with description 'ISO 8601 or now', providing 100% coverage. The description adds no extra semantic detail beyond what the schema already states, so baseline 3 applies.

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 ('Get') and resource ('detailed information about a date'), listing concrete attributes (day of week, ISO week number, day of year, leap year, quarter), which clearly distinguishes it from sibling tools like date_math, date_diff, and format_date.

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?

No guidance on when to use this tool versus alternatives is provided. The description doesn't mention when users should prefer date_info over date_math or format_date, nor does it note any prerequisites or limitations.

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