set_active

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

With no annotations provided, the description carries the full burden and does so thoroughly. It discloses the mechanism (Shift keypress every two minutes), the impact on idle time and sleep, that it only starts and ends sessions, the schedule override behavior, and that certain conditions (no Accessibility permission, battery restrictions) are not reported as errors but surfaced via 'active' and 'status'. This level of transparency is exceptional.

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?

Although lengthy, every sentence adds value: purpose, distinction, mechanism, duration options, edge cases, and return values are all covered without redundancy. The structure is logical, front-loaded with the core purpose, and efficiently uses paragraphs to group related concepts.

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 3 parameters, no output schema, and no annotations, the description is remarkably complete. It explains all parameters, return values ('active' and 'status'), error handling (non-error conditions), interaction with the schedule, and the relationship with set_awake. Nothing essential is omitted for an agent to correctly invoke and interpret the tool.

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 significant meaning beyond the schema. It explains 'until' with examples ('17:00', ISO-8601 timestamp) and clarifies that it ends at the next such moment, defines 'minutes' as a countdown, and explains the 'neither' case (runs until switched off or default timeout). This enriches the schema where the 'on' parameter has no description.

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 purpose: 'Turn stay-active on or off, so chat apps go on showing the user as available instead of Away.' It distinguishes itself from sibling set_awake by explaining the mechanism (posting a Shift keypress every two minutes) and why it's the correct choice for chat app status, making the purpose specific and 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?

Explicitly tells when to use this tool over set_awake ('Pick this over set_awake by what is being protected') and explains the relationship between them ('stay-active implies keep-awake and there is no need to turn both on'). It also provides clear guidelines on choosing duration parameters ('until' vs 'minutes') and states the default behavior when neither is given.

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