Graphite: look at the canvas

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

Annotations cover the safety profile (readOnly, idempotent, closed-world), and the description adds substantial context beyond them: no disk writes, the default scale rationale, and concrete failure modes with recovery guidance (EXPORT_FAILED for layerless documents, BRIDGE_TIMEOUT with retry). This is exactly the behavioral detail annotations cannot express.

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?

One tight paragraph, front-loaded with the core action, then usage, then constraints, then error handling. Every clause carries information; nothing is padding.

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?

With an output schema covering return values and annotations covering safety, the remaining gaps an agent needs — when to call it, cost implications, and failure/retry behavior — are all present. Complete for this tool's complexity.

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 reinforces the single parameter's tradeoff ('default scale 0.5 keeps the image small') in plain language that complements the schema's 'larger previews cost more context' note. It adds modest framing rather than new syntax.

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?

Starts with a specific verb+resource: 'Render the active document to a PNG and return it as an image.' It also distinguishes itself from the sibling graphite_export by stating 'Nothing is written to disk,' so an agent can tell the preview apart from the export tool without opening either 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?

Gives clear context: 'Use it after inserting artwork to check composition, alignment and missing elements before iterating.' That is explicit when-to-use guidance. It stops short of naming graphite_export or graphite_get_document as the alternative for the non-visual case, so it is not a full 5.

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