Preview Brief

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

Annotations already declare idempotentHint=true, destructiveHint=false, and readOnlyHint=false, so the agent knows this is a repeatable, non-destructive write. The description adds real value beyond that by disclosing the output artifacts (brief file + recordings dirs), the workflow constraint ("real footage only"), and the downstream verification path.

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?

Front-loads the concrete action, then structures guidance with "Use when:" and "Returns:" labels. Efficient overall, though the multi-line wrapping is slightly less scannable than a tight prose sentence.

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?

An output schema exists, so return-values need not be explained further, and the description still summarizes the return shape. Workflow placement and the follow-up tool are covered; only an explicit overwrite/preconditions note is absent, and that lives in the schema.

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 app_dir, message, and overwrite are already fully documented in the schema. The description adds no parameter-level meaning beyond what the schema provides, which is the baseline 3 case.

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?

States a specific verb and resource: write marketing/preview/BRIEF.md from app.spec.json and create recordings folders. This is clearly distinguishable from preview_check (validation) and the recording/authoring steps it routes the agent toward.

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?

"Use when: starting the App Preview video" gives explicit timing, and it names the follow-up flow (record the real app, author with the hyperframes skill) and the verification tool preview_check. No explicit when-not condition is given, which is the only gap.

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