queue_next

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

With no annotations at all, the description carries the full behavioral burden. It discloses that this is a write operation (' (1 write)'), that it performs a tail insert rather than an insert-next, and why (Spotify has no insert-next API). It also signals that a temp-playlist workaround exists. This is genuinely useful contextual behavior beyond what the schema structure conveys.

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 definition is compact — roughly three clauses — and front-loads the main action before the behavioral caveat. The 'Optionally notes temp-playlist workaround' fragment is slightly awkard as meta-instruction, but it earns its place by flagging an alternative strategy in few words. No redundancy with the schema.

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 4-parameter mutation with no annotations and no output schema, the description covers the key behavioral trait (tail insert) but omits response/return behavior (notable given the response_format parameter exists), device prerequisities, and any relationship to sibling queue tools. Adequate at the core, with clear gaps about what happens when the tool is invoked.

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%, so the schema already documents all four parameters (uri, dry_run, device_id, response_format). The description adds little parameter-level meaning beyond echoing 'track/episode,' which the uri schema field already covers ('Spotify track or episode URI'). The baseline 3 applies.

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 first clause, 'Queue a track/episode to play next,' names a specific verb and resource. The parenthetical 'tail insert with honest disclosure — Spotify has no insert-next API' clarifies that despite the tool name suggesting insert-next, it appends at the queue tail, which is valuable disambiguation for an agent. It stops short of a 5 because it does not explicitly differentiate from the sibling add_to_queue, which could plausibly appear to serve the same purpose.

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?

No when-to-use or when-not-to-use guidance is provided. With siblings like add_to_queue, queue_next_episode, and queue_replace_via_playlist in the toolset, the description never tells an agent how to choose between them. The 'Optionally notes temp-playlist workaround' line reads as a meta-instruction to the model rather than user-facing selection guidance.

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