Start timer

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

With no annotations, the description carries the transparency burden. It discloses the overlapping-entry behavior and template application, but does not mention return value, what happens if a timer is already running (though implied), or permission requirements. Missing key behavioral details like whether it returns the created time entry.

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 sentences, front-loaded with the primary action, followed by crucial usage guidance. No filler or redundancy; 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?

Given the tool has 9 optional parameters, no annotations, and no output schema, the description covers key usage points but omits return value and default behavior when certain params are absent. It is adequate but not fully complete for the complexity level.

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 covers 100% of parameters, giving a baseline of 3. The description adds value by explaining the relationship between issue_number/issue_title and the description template, and that the description parameter overrides the template. This goes beyond the schema descriptions.

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 starts with the specific action 'Starts a new running timer', clearly distinguishing it from siblings like stop_timer and create_time_entry. It also indicates the resource is a timer, which is unambiguous.

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?

Provides explicit guidance: 'Prefer stopping any existing timer first unless the user wants overlapping entries.' This explains when to use the tool and the conditional behavior. It also gives an instruction about passing issue_number/issue_title when description is omitted, which is useful usage context.

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