get_currently_playing_song

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds no behavioral context beyond that—it doesn't disclose what happens when no track is playing, whether a media provider needs to be active, or any state-dependent behavior. It merely lists return fields, which is more about output than behavior.

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?

A single sentence that starts with the core purpose ('Current playback status') and efficiently lists the returned fields. No filler, no redundancy—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?

For a no-param read-only tool with strong annotations, the description is mostly sufficient, but the absence of an output schema means the field list is the only return specification. It doesn't clarify types, nullability, or the no-track-playing edge case, leaving some ambiguity about how to interpret the result.

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?

With zero parameters and 100% schema coverage, the schema is already complete. The baseline for no parameters is 4, and there is no parameter information for the description to add.

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 clearly states the resource (currently playing song) and enumerates the specific fields returned (status, title, artist, album, album art URL, position), distinguishing it from control tools like toggle_play_pause. However, it doesn't explicitly contrast with sibling retrieval tools like search_and_play or spotify_devices, so it stops short of full differentiation.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention that it's the go-to for reading playback info, nor does it reference the many media control or Spotify siblings that might also provide context. The agent must infer usage entirely from the name and field list.

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