focus_start_timer

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

Beyond the minimal fact that it starts a timer immediately, the description discloses very little. No annotations are present, so the description must carry the full burden. It omits critical behaviors like whether an existing timer is automatically stopped, how the 'start' parameter interacts with 'immediately', or any permission or side-effect requirements. This is insufficient for a state-changing operation.

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 sentence, front-loaded with the essential action. The prefix 'Toggl Focus/2.0:' is unnecessary noise but does not significantly hinder readability. Overall, it is concise and to the point, though it could list examples more efficiently.

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 has 10 parameters, no output schema, and no annotations, the description is severely incomplete. It fails to describe the return value, side effects on existing timers, or the meaning of many optional parameters. For an agent to use this tool correctly, more context is needed.

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 description coverage is only 40%, so the description must compensate. It mentions 'type defaults to activity' and 'Optional task_id/project_id/description,' but this largely repeats schema information. It does not explain the meaning or usage of tag_ids, billable, time_block_id, or other parameters. The description adds little value beyond what the schema already provides.

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 tool's action: 'start a timer immediately.' It specifies the primary verb and resource, and distinguishes this from sibling tools like focus_stop_timer or focus_get_current_timer. The mention of defaults ('type defaults to activity') adds precision without ambiguity.

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 guidance is provided on when to use this tool versus alternatives such as focus_create_time_entry or when to stop an existing timer. The description implies immediate start but does not state any exclusions, prerequisites, or trade-offs. There is no mention of scenarios where a different tool would be more appropriate.

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