Render canvas

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered; the description adds real behavioral context the annotations lack — the return is a downscaled PNG bounded by maxSize on the longest side, and output can be restricted to specific element ids. It doesn't say what happens with invalid ids or missing elements, keeping it off a 5.

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 short sentences, the return type and purpose front-loaded, with the sizing constraint second. No filler and nothing 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?

For a read-only render tool with full annotation coverage and no output schema, the description covers what is returned, the optional element filter, and the size bound — enough to call it correctly. Minor gaps remain around defaults for maxSize and error behavior on unknown ids.

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 only 50%, and the description compensates by defining maxSize's actual behavior (downscale on the longest side) where the schema gives only numeric bounds, and by clarifying that ids narrows the render to those elements. tabId and beautify are left entirely to the schema, which does document them adequately.

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 ("Return a PNG of the canvas") plus a scoping option (only the given element ids), and the phrase "so you can see what the user sees" implicitly separates it from export-style siblings like snipaya_export. It does not name any sibling explicitly, so it stops short of the top score.

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?

Usage is implied by "so you can see what the user sees" — this is the visual-inspection tool. But there is no explicit when-to-use/when-not guidance and no pointer to snipaya_export or snipaya_redact as alternatives for file output or hidden content.

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