balance_playlist_pairs

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

With no annotations, the description carries the burden and does disclose the key behaviors: returning a read-only PLAN by default, committing only when dry_run=false, and incurring 'N GETs + moves' on commit. It could add that committing moves tracks, but 'moves when committing' and 'surplus moves' imply it.

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 sentences plus a quota note, front-loaded with the main action and scope. Every phrase carries information: action, resource range, metric choices, algorithm, safe default, and cost.

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?

Despite having no output schema, the description tells the agent what the tool returns ('the move PLAN') and what affects it (dry_run). All parameters are documented in the schema, and the quota note clarifies cost, so nothing essential is missing for correct invocation.

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 schema already covers all 5 parameters with descriptions, so the baseline is 3; the description adds useful cross-cutting meaning by tying dry_run to 'returns the move PLAN read-only' and by summarizing balance_by as 'track counts or runtimes.' It does not go into max_results or response_format, but the schema already handles those.

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 names a specific action ('Plan (and optionally commit) rebalancing'), a bounded resource scope ('2–10 playlists'), and the balancing metrics ('track counts or runtimes'). It also explains the mechanism ('computes surplus moves from the larger to the smaller'), making the tool easy to distinguish from generic playlist merge/interleave siblings.

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 gives clear use context: when playlists need balancing to similar counts/runtimes, and it explicitly notes dry_run defaults to TRUE for read-only planning. It does not name alternatives or when-not conditions, so it stops short of a 5.

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