Browser set viewport

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

Without annotations, the description should disclose behavioral nuances. It reveals the tool is intended for snapshot/screenshot preparation, which is helpful, but it doesn't mention side effects, session requirements, or persistence. The core action is clear, but the behavioral footprint is underexplained.

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 description is a single, front-loaded sentence with no filler. Every word adds meaning, and the structure is clear.

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 simple parameter-setting tool with no output schema, the description adequately covers its primary function and timing. It may not detail edge cases, but it provides sufficient context for the tool's intended use within the broader browser debug toolset.

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?

The description indicates the tool adjusts 'viewport size' (width/height) within a 'browser debug session' (session_id), but it doesn't explicitly explain each parameter's format or constraints. Since schema coverage is 0%, the description offers minimal compensation, though the parameter names are self-explanatory.

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 uses a specific verb ('Set') and resource ('viewport size for a browser debug session page'), clearly distinguishing it from siblings like browser_snapshot and browser_screenshot. It also adds context about its purpose ('before snapshot or screenshot checks'), making its role unambiguous.

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?

The phrase 'before snapshot or screenshot checks' explicitly indicates when to use this tool relative to siblings. It doesn't provide exclusions or alternative tools, but the timing is clear and practical.

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