stop_timer

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

With no annotations, the description carries the full burden, and it does disclose two real behaviors: a Redmine time entry is created and the current user is auto-detected. It omits what happens when no timer is running, whether an activity defaults, and whether failure leaves the timer intact — significant for a mutation.

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 tight sentences, zero filler, with the primary action and its side effect front-loaded.

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 mutation with no annotations and no output schema, an agent still lacks the failure semantics (no active timer), permission requirements, and any sense of what is returned. The core happy path is covered, but the edge behavior an agent needs before calling is not.

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 100%, so all four parameters are already documented, including the hours override and the list_time_entry_activities pointer for activity_id. The description adds only the implicit fact that no user parameter is needed because the user is detected automatically.

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?

States a specific verb+resource ('Stop the timer for an issue') plus the consequential side effect ('log the elapsed time to Redmine as a time entry'). It does not distinguish itself from the sibling cancel_timer, which is the critical ambiguity for an agent choosing between stopping-and-logging versus discarding.

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?

No when-to-use or when-not-to-use guidance is given. The description never says the timer must already be running, never mentions cancel_timer as the non-logging alternative, and never contrasts with log_time for manually entering time, leaving the agent to infer the selection rule.

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