stop_timer

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the primary action, but it does not explain what happens if no timer is running, if multiple timers are running and no timesheet_id is supplied, or whether stopping a timer is reversible. These edge cases are not addressed, leaving a moderate transparency gap.

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 extremely concise: one clear purpose sentence followed by a minimal parameter note. There is no filler, and the most relevant usage rule is front-loaded. Every sentence earns its place.

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 tool with a single optional parameter, the description covers the main call path and the omit-when-only-one rule. The output schema exists, so return value documentation is likely covered elsewhere. The only notable gap is the missing rule for the multiple-running-timers case, which could cause an ambiguous or invalid call.

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 only defines timesheet_id as an optional integer, but the description adds meaning: it selects which entry to stop and may be omitted when only one timer is running. This is meaningful semantic guidance for the single parameter. It could be improved by pointing to where to find the timesheet_id, such as active_timers or list_timesheets.

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 operation as 'Stop a running timer,' which is a specific verb and resource. While the phrasing closely mirrors the tool name, the addition of 'running' and the parameter note makes the purpose concrete. It is naturally distinct from siblings like start_timer and restart_timer.

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 a clear trigger for use: a running timer needs to be stopped. It adds a conditional usage rule for the optional parameter ('Omit to stop the only running one'), which guides the agent on how to decide whether to pass timesheet_id. It does not explicitly mention alternatives, but the unique operation makes the choice obvious.

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