List movies

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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description's 'List' action aligns with a read-only operation. The description adds minimal behavioral context beyond the annotations, such as the exact fields returned, but no details about pagination or edge cases.

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 concise sentences, front-loaded with the main purpose. Every phrase adds value: the output fields and the cross-reference to set_movie. No waste or redundancy.

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 simple listing tool, the description fully captures what the tool does, what it returns, and the obvious next step. The output schema likely covers return details, so no further description is necessary.

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?

The single parameter 'device' is fully described in the schema (100% coverage), including the default-device behavior. The description does not add parameter details, but the schema covers semantics sufficiently, 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?

The description uses the specific verb 'List' with the resource 'movies (saved animations)' and clearly states the output fields (id, name, frames, fps) plus the current movie, distinguishing it from sibling tools like list_effects and set_movie.

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?

The description provides clear context for when to use this tool (to list movies and see which is current) and explicitly points to set_movie as the follow-up to play one. It does not explicitly state when not to use it, but the alternative is clearly named.

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