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

With no annotations, the description carries the full burden and largely succeeds: it discloses the 2-credit cost, the mandatory prior measurement step with a concrete download URL and command, and the exact return shape (score /100, checks table, numbered frame-level fixes, then JSON). It never explicitly states that the tool is side-effect-free, which is the one gap given zero annotation coverage.

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 purpose, then prerequisites, returns, and cost in a logical order; every sentence carries information. It is dense and embeds a shell one-liner and a credit cost, which makes it heavier than ideal, but nothing is redundant.

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?

No output schema exists, so the description must describe returns — and it does (score out of 100, checks table, numbered fix list, JSON). Combined with prerequisite steps, cost, and platform-specific loudness targeting, an agent has everything needed to invoke it 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 coverage is 100%, so the baseline is 3; the description adds value beyond the schema by explaining how to obtain the `render` payload (the curl-and-unzip starter kit plus measure.mjs) and by clarifying that fix frames are expressed at the render's own frame rate. It does not elaborate on `id` beyond what the schema already documents.

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 — checking a rendered video against the reference's measured timeline — and enumerates exactly what it evaluates (cut timing, pace, brightness, motion, loudness, format). An agent can distinguish it from siblings like get_frames, plan_video, or storyboard without opening any schema.

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?

Opens with the triggering condition ("After rendering a video from a reference") and prescribes the prerequisite workflow of measuring the render first. It also tells the agent how to iterate (fix, re-measure, check again). It lacks explicit when-not-to-use or a named alternative tool, so not quite a 5.

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