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

Annotations already declare readOnlyHint=false, destructiveHint=true and openWorldHint=false; the description adds genuinely new behavioral context by stating the no-op condition and what is returned afterwards. It stops short of explaining what 'destructive' means here (interrupting playback, no undo of the skip), which would have closed the gap.

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?

Three short sentences: the action first, then the precondition, then the return shape. Every sentence carries information and none repeats the title or annotations.

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 simple no-arg playback command with an output schema, the description covers action, precondition and post-state, which is enough to invoke it safely. Edge cases such as what happens with no queue or at the last track are unstated but minor given the output schema reports player state.

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?

There is a single optional parameter, and the schema already documents it fully as 'Ignored; kept for older clients.' Schema coverage is 100%, so the baseline of 3 applies; the description adds nothing about the parameter, though it also needs to add nothing.

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 states a specific verb and resource ('Skips to the next track in the Music app'), which unambiguously separates it from music_previous_track, music_play and music_pause. It doesn't explicitly name a sibling, but the operation is self-evidently distinct, so the agent doesn't need the schema to disambiguate.

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?

It supplies one useful precondition ('Does nothing when the Music app is not open'), but gives no explicit guidance on when an agent should skip versus call music_play with a specific track, or how this pairs with music_previous_track. Usage is implied by the verb rather than explained.

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