Launch pictures

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

Annotations already declare openWorldHint=true and non-idempotent, and the description adds meaningful behavior beyond them: opaque PNG output, files written to stills/ and indexed in STILLS.md, and the side effect that supplying a site triggers film planning first. It does not discuss permissions or failure modes, but the added context is substantial.

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-loaded with the core action and platform list, then the input-mode rule. Dense but every clause carries information; the version/machine parenthetical is the only low-value fragment.

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, yet the description still notes the job_id/wait behavior and where artifacts land. For a 4-parameter tool with full schema coverage, this is close to complete.

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%, so the baseline is 3, but the description goes further by decoding the enum values (ph = Product Hunt, og = link previews, x, play, chrome) and clarifying that source may be a website or an existing film.json. That is genuine meaning beyond the schema.

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 ('Makes the pictures a launch needs') and enumerates the exact platforms and output artifacts (stills/, STILLS.md), which clearly separates it from make_launch_film and render_launch_film.

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?

Explains the two input modes ('Give a site and it plans a film first, or give a film.json so the pictures match the film'), which is real usage guidance. It stops short of explicitly saying when to prefer this over make_launch_film or plan_launch_film.

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