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

Annotations already flag destructiveHint=true and openWorldHint=true; the description adds the operationally important consequence that 'Queue changes can affect live output,' which is not derivable from the hints. It stops short of describing ordering behavior, duplicate handling, or what the response contains.

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?

Front-loads the purpose, then the risk warning, then parameter guidance, then the mirrored endpoint. Four dense sentences with little waste, though the REST-endpoint sentence is the least essential for an agent.

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?

Covers purpose, risk, and both payload variants for a destructive, no-output-schema mutation tool. Remaining gaps (return value, ordering guarantees, auth requirements) are modest given the annotations and full schema coverage.

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 100%, so baseline is 3, but the description adds real meaning beyond the schema: the .mp4 URL constraint for external-videos and the concrete shape of items per queue type. It does not clarify whether items append at the end or their position semantics.

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 ('Append items to a stream queue') and the per-queue-type payload semantics, which cleanly separates it from siblings like remove_from_stream_queue, reorder_stream_queue, and get_stream_queue. An agent can identify the operation without opening the 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?

It routes the caller by queue type (media UUIDs for video/audio/audio-secondary vs {url, name} for external-videos) and points to list_media as the way to obtain UUIDs. It gives clear context but does not state when not to use this tool (e.g., to reorder or remove, use the sibling tools).

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