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

With no annotations, the description bears the full behavioral burden. It discloses what is computed but does not state whether the operation is pure/read-only, what date input formats are accepted, timezone handling, or error behavior. This leaves significant gaps for safe and correct invocation.

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, front-loaded sentence that communicates the essential return values with no unnecessary words. It is appropriate for a simple utility tool.

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 time computation tool with a nested input schema and no output schema or annotations, the description is incomplete. It explains what is returned but omits critical input formatting details and usage context, which an agent needs to call the tool correctly.

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 0% and the description adds no information about the input date beyond the word 'date', which merely restates the schema property name. It does not specify the expected date string format (e.g., ISO 8601, YYYY-MM-DD) or any constraints, leaving the parameter semantics entirely undocumented.

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 return values: ISO 8601 week number, ISO year, and ISO weekday for a date. It is specific about the computation, making it distinguishable from siblings like time_format or time_parse. However, it does not explicitly name or compare against alternatives, so it falls short of the top score.

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 provides no guidance on when to use this tool versus the many other time-related siblings. It only describes the output, not the context or prerequisites for invocation. An agent must infer usage entirely from the tool name and purpose.

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