skip_previous

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

With no annotations provided, the description carries the full disclosure burden, and it delivers the single most valuable hidden trait: the restart-current-track-if-more-than-3-seconds-in behavior. This is exactly the kind of nuance an agent could not infer and confirms this is a state-mutating operation without the annotations saying so.

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 short sentences with zero filler. The core action is front-loaded in the first sentence and the critical edge-case behavior in the second. Every word 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?

This is a low-complexity tool — one optional parameter, no output schema, no nesting — and the description covers the action plus its key behavioral trap. A return-format description would be marginally useful but is not critical for a transport control like this.

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% — 'device_id' is already documented as 'Target device ID' in the input schema, so the description need not repeat it. The description adds no parameter-level detail, which is acceptable at baseline given full schema coverage.

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?

States a specific verb and resource — 'Skip to the previous track' — that is unambiguous and self-evidently distinct from its skip_next sibling. It reads as a real action description, not a tautology of the tool name, and the direction ('previous' vs 'next') is inherent to the name.

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 delivers a useful behavioral nuance (restarting the current track past 3 seconds) but gives no explicit routing guidance — no 'use this when…' or 'instead of skip_next/seek…'. Selection context is implied by the tool name rather than spelled out.

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