youtube_play

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It discloses one key behavior — that no browser is launched — and implies the output is a URL, but it does not state whether the tool makes network calls, how instances are chosen, whether the video_id is validated, failure behavior, or the return format.

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 description is a single efficient sentence with no wasted words, and it front-loads the core purpose and key behavioral caveat. It is appropriately sized for a simple tool, though it sacrifices informative content for brevity.

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 tool with 5 parameters, no output schema, and no annotations, this description is incomplete. An agent still lacks definitions for parameters like listen and sponsorblock, does not know what structure the returned URL takes, and cannot predict side effects — all of which the description should supply given the absence of structured context.

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 0%, so the description must compensate for the 5 parameters, but it adds nothing about listen, quality, autoplay, sponsorblock, or video_id beyond what the bare names suggest. The output framing ('browser-ready URL') weakly implies the parameters configure the generated URL, which is some value, but well short of adequate compensation.

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 uses a specific verb ('Generate') and resource ('Piped or Invidious URL'), making the tool's output clear. It implicitly differentiates from siblings by describing a URL-generation function rather than search or metadata retrieval, though it never names the siblings explicitly.

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 guidance is given on when to choose this tool over youtube_search or youtube_video, and no alternatives or exclusions are mentioned. The phrase 'without launching a browser' hints at a programmatic use case, but the conditions that would select this tool are left entirely to inference.

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