Get per-device time breakdown

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

With no annotations provided, the description carries the full disclosure burden. It does this excellently by specifying what each device reports (active/passive seconds, days active, first/last seen, platform, isCurrent flag) and, most importantly, revealing the DISTINCT 30s-bucket counting semantics and the resulting double-counting caveat versus get_report. This is critical behavioral information an agent needs to interpret results correctly.

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 efficient and well-structured. Four sentences, each earning its place: scope, per-device fields, the isCurrent flag, and the crucial bucket-counting caveat. Information is front-loaded with the primary purpose and no filler or redundancy.

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?

For a single-parameter read-only breakdown tool with no output schema and no annotations, the description is remarkably complete. It covers the intended audience, output fields, the special isCurrent marker, and the mathematical semantics that prevent misinterpretation. An agent has everything needed to call the tool and interpret the response.

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 description coverage is 100% for the single 'period' parameter, so the schema already fully documents the allowed values. The description adds no additional parameter-level meaning, but it doesn't need to; the baseline of 3 applies because the schema does the heavy lifting.

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 function: 'Time per device for users who run Vetroscope across multiple machines (or paired with the browser extension).' It identifies the resource (devices) and distinguishes itself from get_report by explicitly noting that summing device totals can exceed get_report.totalSeconds, separating it from the total-report sibling.

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 gives a clear context for when the tool is relevant: users running Vetroscope on multiple machines or with the browser extension. It implies this is the device-level breakdown tool and references get_report as the total counterpart, but it does not explicitly state 'use this when you need device-level detail' or name all alternatives. Still, the context is sufficient for an agent to select it appropriately.

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