get_datetime

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

With no annotations provided, the description carries the full burden. It discloses that the tool returns formatted datetime with day of week always included, which is useful behavioral context. However, it doesn't mention potential errors (e.g., invalid timezone), rate limits, or authentication needs, leaving some behavioral aspects unspecified.

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 efficiently structured with a clear purpose statement followed by well-organized sections for Args and Returns. Every sentence adds value: the first states the core function, and the subsequent lines provide essential parameter and return details without redundancy.

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 low complexity (2 optional parameters) and the presence of an output schema (which handles return values), the description is mostly complete. It covers purpose, parameters, and return behavior adequately. However, it could slightly improve by mentioning error cases or default timezone behavior more explicitly.

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 schema description coverage is 0%, so the description must fully compensate. It provides detailed semantics for both parameters: 'tz' is explained as an IANA timezone with examples and default behavior, and 'format' lists specific options with their meanings. This adds significant value beyond the bare 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 verb 'Get' and the resource 'current date and time with day of week', making the purpose specific and unambiguous. It distinguishes from siblings like 'convert_time' or 'relative_time' by focusing on current datetime retrieval rather than conversion or relative calculations.

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 context through the parameter explanations (e.g., timezone handling, format options), but does not explicitly state when to use this tool versus alternatives like 'get_week_year' or 'days_in_month'. It provides clear parameter guidance but lacks explicit sibling differentiation.

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