start_timer

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

No annotations are provided, so the description carries full burden. It only says 'Start a new Toggl time entry', but does not disclose critical traits such as whether it stops an existing timer, what happens on duplicate timers, or authentication requirements. This lack of detail leaves the agent unprepared.

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 concise sentence that front-loads the purpose. Every word is necessary; there is no redundancy or extraneous information.

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 simple tool (3 params, no output schema, no annotations), the description covers the basic action but omits important context like what happens if a timer is already running, error conditions, or how tags are used. It is adequate but incomplete for a production agent.

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?

All parameters have descriptions in the schema (100% coverage). The description essentially repeats that a description is required and project name is optional, adding no new interpretation or nuance. Thus it contributes no extra value beyond the schema.

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 verb 'Start' and resource 'Toggl time entry'. It mentions the key input (description and optional project name), making the purpose clear. However, it does not differentiate from sibling tools, but siblings are sufficiently distinct that lack of explicit differentiation is not critical.

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 no guidance on when to use this tool vs alternatives. It does not mention that an active timer may be overwritten or that starting a new timer might stop the previous one. There is no context about prerequisites or when not to use it.

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