check_out

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

No annotations are provided, so the description carries the behavioral burden. It discloses that running timers get stopped with an auto note, which is useful. However, it doesn't clarify what happens if no timers are running, what the return value is, or whether this is destructive/idempotent.

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?

Two short sentences, zero wasted words. Front-loads the primary purpose and adds one key behavioral nuance. Appropriate length for a zero-parameter 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 parameterless tool in a time-tracking family, the description covers the core purpose and the key side effect (stopping timers). It could mention idempotency or behavior when no timer is active, but this is near-complete for the tool's simplicity.

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 tool has zero parameters and 100% schema coverage (no params to document). The description adds the behavioral context about timers being stopped, exceeding the baseline for a 0-parameter tool.

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 action (check out for today) and adds a meaningful behavioral detail: running timers are stopped with an auto note. This distinguishes it from check_in and stop_timer siblings, though it's a bit brief.

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 the end-of-day context ('for today') and the timer-stopping behavior. While it doesn't explicitly name alternatives like stop_timer or check_in, the sibling set makes the distinction apparent enough.

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