Set movie

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

Annotations already flag this as mutating (readOnlyHint=false), so the description doesn't need to re-state that. It adds value by explaining the device switches to movie mode and plays, which is beyond the annotation. No contradictions.

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, front-loaded with action and purpose, no wasted words.

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 2-parameter tool with annotations and full schema coverage, the description is complete. It covers how to obtain the id, what the tool does, and the effect. No output schema needed.

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% with descriptive parameter text, so the baseline is 3. The description doesn't add significant parameter semantics beyond referencing list_movies, which the schema already does.

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 a specific verb ('Select') and identifies the resource ('saved movie by numeric id') and the action ('switch device into movie mode and plays'), clearly distinguishing it from sibling tools like set_effect or set_mode.

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 provides an explicit prerequisite ('Call list_movies first to see the available ids'), which is essential usage guidance. It doesn't explicitly exclude alternatives, but the context makes it clear when to use this tool.

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