Plan Emphasis Zoom Keyframes

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered. The description adds that the tool is local-only and deterministic and that it never changes Premiere, which reinforces the read-only behavior. It stops short of describing rate limits, auth needs, or output structure, but the output schema handles the latter.

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 tightly written sentences that front-load the core purpose and then add the key behavioral constraint. Every clause contributes useful information—effect style, input sources, controls, output destination, and side-effect guarantee—with no filler. It is appropriately sized for a 17-parameter planning tool.

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 rich input schema (100% coverage, nested objects) and the existence of an output schema, the description only needs to orient the agent, which it does completely. It covers purpose, input modes, output destination, and the no-side-effect guarantee. Annotations carry the safety profile, so no critical information is missing for correct invocation.

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%, so the schema already documents all 17 parameters in detail; per the rubric, that establishes a baseline of 3. The description mentions cooldown, easing, hold controls, and subject-anchored Position, but these map directly to already-described schema fields rather than adding new semantic guidance. It does not provide syntax or interaction rules beyond what the schema supplies.

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 states a specific planning verb and resource: 'Plan CapCut-style punch-in zoom keyframes (Motion Scale + subject-anchored Position).' It distinguishes the tool from mutators like add_keyframe by clarifying that it only produces a plan and never changes Premiere. The input modes (word timeline or supplied trigger times) and downstream consumers (automate_effect_parameters_uxp or add_keyframe) make the role unambiguous.

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 specifies the two input contexts—a word timeline or supplied trigger times—and names the downstream tools that consume the plan, giving clear usage context. However, it does not explicitly say when to prefer this planner over calling add_keyframe directly or over other planning siblings. The guidance is clear enough for selection but lacks explicit exclusion criteria.

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