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

The only annotation is destructiveHint=false, so the description usefully adds that this is an append operation mirroring POST /api/v1/streams/{stream}/queues/{type}, plus a hard validation rule (url must end in .mp4). It does not cover idempotency, ordering, limits, or auth requirements, but it adds real behavior beyond the annotation.

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 tight sentences, front-loaded with the core action, then the format branching, then the endpoint reference. Every sentence carries information an agent needs to construct a correct call.

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 output schema, the description doesn't say what the call returns, which is a minor gap for a mutation tool. Everything else needed to invoke it correctly — type-to-format mapping, validation, UUID source — is present.

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 the baseline is 3, but the description genuinely adds meaning: the items format is conditional on type (UUID array vs {url, name} objects), the .mp4 constraint, and the list_media pointer. These go beyond the schema's terse property descriptions.

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+resource ('Append items to a stream queue') and immediately differentiates itself from siblings by spelling out per-queue-type item shapes. An agent can distinguish this from remove_from_stream_queue and reorder_stream_queue without opening any 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 conditional guidance: which item format applies to which queue type, and routes the agent to list_media to obtain UUIDs. It stops short of explicit when-not-to-use or naming the alternative siblings (remove_from_stream_queue, get_stream_queue).

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