Play a video live into the broadcast

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

With no annotations, the description carries the burden and does real work: it discloses the viewer-visible 'Prerecorded' mark, that viewers cannot skip or save, the live/immediate nature, and the single-video exclusivity rule. It doesn't cover failure behavior (e.g., invalid path) or whether the call blocks until the video ends, which keeps it below a 5.

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?

Three short sentences, zero filler, with the core action front-loaded and the exclusivity/termination rule at the end. Every clause carries information an agent would otherwise have to guess.

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 two-parameter action tool with no output schema and no annotations, the description covers what it does, its visible side effects, and its stopping counterpart. The main remaining gap is the absence of any mention of what the call returns or how path errors surface, which matters when there is no output schema to fall back on.

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%, and the schema already explains both 'path' (local file, .mp4/.webm) and 'meeting_id' (from create_broadcast/join_broadcast). The description's phrase 'from this computer' reinforces the path semantics but adds no format or constraint detail beyond the schema, so 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?

States a specific verb and resource ('Plays a video file from this computer live into the broadcast') plus the audience scope ('for everyone watching'). It explicitly names the sibling that ends the action (stop_video), so an agent can distinguish it without opening a schema.

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?

Gives clear operational context: it happens 'now' and only 'one video at a time,' with stop_video named as the terminating counterpart. It stops short of routing against other content-sharing siblings such as share_content, so the agent must infer which tool to use for non-video content.

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