countdown

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 key behavioral traits: it calculates a countdown, returns remaining time components and past status, and implies it uses the current time as the start point. However, it lacks details on error handling, input validation, or performance aspects like rate limits.

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, well-structured sentence that efficiently conveys the tool's purpose, input context, and output details without any wasted words. It's appropriately sized and front-loaded with essential 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?

Given the tool's moderate complexity (2 parameters, no annotations, no output schema), the description is adequate but has gaps. It explains what the tool does and returns, but without an output schema, it doesn't detail the return structure (e.g., object format). For a calculation tool, this is minimally viable but could be more complete.

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 description coverage is 100%, so the schema already fully documents the parameters. The description adds no additional parameter semantics beyond what the schema provides, such as examples or constraints. This meets the baseline for high schema coverage.

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 specific action ('calculate a countdown'), the resource ('from now to a target date/time'), and distinguishes it from siblings by focusing on countdown calculation rather than business days, time conversion, or other date/time operations. It explicitly mentions the return values, which helps differentiate its purpose.

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 by specifying 'from now to a target date/time,' which suggests it's for countdowns relative to the current moment. However, it doesn't explicitly state when to use this tool versus alternatives like 'date_diff' or 'manage_countdown,' leaving some ambiguity about sibling tool differentiation.

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