Render page

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

Annotations declare readOnlyHint and openWorldHint, and the description adds real behavioral detail beyond them: it runs a headless browser, waits for window.map to finish loading before drawing, reports page errors/warnings/failed requests/camera, and returns what the script evaluates to. It does not cover timeout behavior or sandboxing of arbitrary page JS, which openWorldHint implies is relevant.

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?

The core action is front-loaded in the first clause, and the remaining sentences each add a distinct fact (outputs, input modes, window.map timing, script evaluation). Sentences are long and clause-heavy, but few words are wasted.

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 no output schema, the description carries the return-value burden and does so: screenshot plus errors, warnings, failed requests, camera, and the script result. For a 5-parameter tool with a mutation-free but open-world execution model, it is close to complete, missing only timing/limit behavior.

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 60%, and the description compensates: it explains that path is served together with the files in its folder, that url points at a page (developer server), and that script runs before the screenshot and its evaluated value is returned. Only width/height are left implicit, which are self-evident from their names and bounds.

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 and resource chain (loads a page in a headless browser, returns a screenshot) plus the secondary outputs (errors, warnings, failed requests, camera). It explicitly contrasts itself with a named sibling: 'which render_style leaves out since a style cannot hold them.' An agent can distinguish this from render_style 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?

It names the alternative (render_style) and the condition selecting this tool: when you need plugins, controls and code that a style cannot hold. It also clarifies the two input modes (HTML file served with its folder, or a URL). It stops short of explicit when-not-to-use guidance or pointing at show_map / preview_style.

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