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

Annotations (readOnly=false, destructive=false) only sketch the safety profile; the description adds substantial context beyond them: it spends PrismPoster credits at a stated price, renders in minutes, saves to the library, blocks under-18/public-figure requests before charging, requires consent for real people in photos, and returns approval_required with nothing running until answered. That is exactly the behavioral detail annotations cannot convey.

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?

Well front-loaded: the core render capability leads, with consequences (credits, approval, refusals) trailing. It is a dense run-on paragraph, so some policy sentences about consent/refusal could be tightened, but nearly every clause carries actionable information.

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?

For a mutation tool with no output schema, the description covers cost, timing, consent, approval flow, and refusal policy well. It does not describe the successful return payload (presumably a job object), though it does note the approval_required answer, leaving a small gap for an agent parsing responses.

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 baseline is 3, but the prose adds real meaning: it explains the cast-vs-performers split (one entry per person vs a Trend's performers filled left to right), that groups of up to 30 are allowed, that speech regenerates the original words, and that scenes keep moves and timing. It goes beyond restating the schema descriptions.

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?

Names a specific verb and resource ('Render a prepared Remake') and defines scope sharply: replace one person or everyone, keep the rest as filmed, change setting/shape/sound. It is clearly distinguishable from remake_start, preview_remake_cast, and quote_job, which are named as prior or adjacent steps.

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?

Gives concrete when-to-use context: poll get_job after, quote_job prices first for free, remake_id comes from remake_start, and approval_required if the person must decide. It stops short of explicit when-NOT-to-use or a direct comparison to preview_remake_cast, so it is clear but not fully exclusionary.

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