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

The annotations already declare readOnlyHint=true, so the description adds a small behavioral note ('Does not film') that clarifies the tool does not produce actual footage. It does not elaborate on output format, async behavior, or other side effects, but given the read-only annotation, the added context is modest.

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?

The description is two short sentences, front-loading the core purpose and then adding a key exclusion. Every word contributes, with no filler 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?

Given the tool's simplicity (3 optional parameters, all documented in schema), the presence of a read-only annotation, and an output schema, the concise description is largely sufficient. It could mention the mutual exclusivity of themeKey and customWorld, but that is already covered in the schema, so the description is adequate.

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?

All three parameters are fully described in the input schema (game, themeKey, customWorld), including the dependency between themeKey and customWorld. The description adds no parameter-specific information, so with 100% schema coverage, the baseline score of 3 is appropriate.

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 names the specific action ('Quote') and resource ('Last Frame opening or next shot'), and explicitly states what it does not do ('Does not film'), distinguishing it from sibling filming tools like start_last_frame. This meets the standard of a specific verb+resource with sibling differentiation.

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 minimal usage guidance: it implies this is for quoting a Last Frame segment but does not explicitly state when to choose this over alternatives. The only exclusion is 'Does not film', which hints that filming is out of scope, but no positive routing to the appropriate sibling is given.

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