helpers_start_timer

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

With no annotations, the description bears full responsibility for behavioral disclosure. It only states the action ('Start a timer') and provides a format hint, omitting details about side effects, authorization requirements, or timer lifecycle.

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 very short with two distinct pieces of information. It is front-loaded, but the brevity sacrifices completeness and fails to fully explain the tool's usage.

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 presence of an output schema, return values are not required, but the description still lacks context on the entity_id parameter and behavior when duration is null. No prerequisites or side effects are mentioned, leaving gaps.

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 description adds the duration format (HH:MM:SS or seconds) which is not present in the schema (0% coverage). However, it does not clarify the 'entity_id' parameter, leaving its meaning ambiguous despite being required.

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 'Start a timer', which is a specific verb and resource. It implicitly distinguishes from sibling tool 'helpers_cancel_timer' by the action of starting versus stopping, but does not explicitly name the alternative.

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 given on when to use this tool versus alternatives. The duration format hint offers some implicit context but fails to explain prerequisites or exclusions.

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