music_play

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

No annotations are provided, so the description carries the full behavioral burden. It discloses that playback starts but says nothing about whether it replaces the queue, whether it requires the Music app to be running, permission/automation prompts on macOS, or what an error looks like when a track_id is invalid. The truncation removes whatever the remaining modes were.

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?

It is front-loaded with the core action, which is good, but the text terminates in an ellipsis mid-sentence, so the structure is broken rather than tight. The surviving fragment is short but incomplete rather than economical.

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?

With no annotations, no output schema, and a schema that exposes no parameters while the description promises two, the definition is not sufficient for an agent to call it correctly. Missing coverage includes the full set of invocation modes, what the tool returns (now-playing state?), and how failures surface.

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 input schema declares zero properties, yet the description references `track_id` and `playlist` as if they were accepted inputs. Even though the 0-param baseline would normally be 4, the description actively advertises parameters the schema does not offer, which would mislead an agent into passing arguments that get rejected.

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?

States a specific verb and resource ("Starts playback in the Music app") and enumerates the three modes of invocation (resume, track_id, playlist), which clearly separates it from siblings like music_pause and music_next_track. The sentence is cut off mid-clause, leaving the final mode incomplete, so it stops short of a fully self-contained purpose statement.

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 three-branch enumeration implies when to use each mode (no args = resume, with track_id = play a specific track, with playlist = play a list), which is genuine routing guidance. However the text is truncated at the third branch and never states exclusions or what to do instead if playback is already active or the target isn't found.

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