capcut_add_text

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It reveals one precondition—that the draft must contain a text layer—but does not explain what the operation does to the timeline, whether it mutates the draft, whether it creates a new segment, or whether it has any destructive effects. This is too thin for a mutation tool.

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 sentences with no filler: the action is front-loaded and the prerequisite is shared concisely. The pointer to CAPCUT_TEMPLATE_DRAFT is an efficient way to reference external context.

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 9 parameters, 3 required, no output schema, and no annotations, this description is under-specified. It does not explain coordinate semantics, time units, duration handling, track selection, or how the template draft is actually used. An agent would likely need additional documentation to invoke this correctly.

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 only 11%, so the description must compensate, but it only clarifies the draft parameter as a text template. No meaning is added for posX, posY, atSec, durSec, fontSize, trackIndex, or text, leaving the agent with mostly self-evident but unverified parameter names.

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 clear verb and resource: 'Add a text overlay.' It also adds a key precondition about requiring a text template draft. However, it does not explicitly distinguish this tool from caption, subtitle, or lower-third siblings, so it stops short of full 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?

It clearly indicates the tool is only appropriate when a text template draft (a draft with a text layer) is available, referencing CAPCUT_TEMPLATE_DRAFT. This is useful contextual guidance, though it does not explicitly list when not to use it or name alternative tools such as capcut_add_subtitles_batch.

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