Check the export on the web runtime

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

With readOnlyHint=true already covering the safety profile, the description adds real value: it discloses the headless-Chrome pipeline, the external dependency, and the metrics produced (silhouette IoU, colour difference, worst frame). It still omits cost/runtime, whether artifacts are written to disk, and failure behavior beyond the missing-browser case, so it is good but not rich.

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?

Two tight sentences, front-loaded with the operation and followed by the metric list and the environment prerequisite. No filler; every clause carries information an agent needs.

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 4-parameter tool with no output schema, the definition covers the mechanism and one prerequisite but leaves the parameters, the shape of the result, and error conditions undocumented. It is enough to understand the tool's role but not enough to invoke it confidently.

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 0%, and the description mentions none of the four parameters. 'project' is required but unexplained (file path? project name?), and 'animations', 'fps', and 'scale' (with their numeric bounds) are entirely undiscussed. The description does not compensate for the schema gap at all.

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 specific verb+resource: renders a fresh export with spine-webgl in headless Chrome and compares every frame against Spine's render, listing the comparison metrics. An agent can tell this is a rendering-fidelity check. It does not name parallel siblings such as spine_unity_check, spine_mix_check, or spine_render_frames, so differentiation is left implicit.

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 supplies a prerequisite ('Needs Chrome or CHROME_BIN'), which is useful context for whether the tool can run at all. However, there is no explicit statement of when to pick this over the similar web/unity/mix-check siblings, nor any exclusion about when not to use it.

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