start_radio

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

With no annotations, the description must carry the full behavioral burden. It usefully discloses the no-seed fallback chain (current song, then top track), but says nothing about whether starting radio interrupts or replaces current playback, clears the queue, or requires any account/auth prerequisites.

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, no filler. The primary behavior is front-loaded and the edge case (no seed) follows immediately after.

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?

An output schema exists, so return values need not be explained, and the sole parameter is fully covered. The remaining gap is side-effect disclosure for a tool that alters playback state, which matters more here than for a read tool.

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 coverage is 0% — 'seed' has no schema description at all — so the description must compensate, and it does: it specifies the accepted format (song name or YouTube URL) and the exact meaning of the empty/default value. Nothing about the single parameter is left ambiguous.

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 gives a specific verb and resource: 'Plays an endless-style radio of songs similar to a seed.' That distinguishes it in spirit from play_songs and dj_play_for_me, though it never names a sibling or explicitly contrasts with them.

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 clearly covers both invocation modes: supply a seed for similarity radio, or omit it to continue from the current song / top track. That is real context for choosing how to call it, but there is no guidance on when to prefer this over the adjacent playback tools (play_songs, dj_play_for_me).

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