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

Annotations already declare readOnlyHint, idempotentHint, closed-world and non-destructive behavior, so the safety profile is covered. The description adds genuinely new behavior: the player continues monitoring queued and generating media until every item is ready, which tells the agent this call waits on readiness rather than failing fast.

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?

Two sentences, zero filler, with the core action and its multi-item carousel scope front-loaded before the readiness behavior.

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?

An output schema exists so return values need not be explained, and annotations cover safety. Purpose plus readiness semantics are complete enough to invoke correctly; only edge behavior (e.g., what happens if an item never becomes ready) is left implicit.

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 fields even document the legacy comma-separated mediaId form and the max of seven additional IDs. The description adds no parameter-level detail beyond that, so the baseline of 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 (display), the resource (Sequencer image/video/audio items), and the presentation mode (one inline carousel). This clearly separates it from the sibling render_image, which serves a single image.

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?

'One or several ... in one inline carousel' implies when to pick this over single-item rendering, and the readiness-monitoring sentence hints at use with pending media. However, it never states an explicit when-not condition or names an alternative tool, leaving usage inferred.

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