browser_screenshot

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

With no annotations provided, the description carries the full burden and does well: it discloses the default return value (base64 PNG), the conditional side effect (saves to disk if path is provided), and the viewport limitation. It does not mention edge cases like file overwriting or page-load timing, but these are minor for a low-complexity tool.

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 sentence that front-loads the primary action, then packs the return format and optional side effect. No filler or redundant detail. Every word earns its place.

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 tool with one optional parameter and no output schema, the description is near-complete: it gives the action, result format, and the effect of the only parameter. It omits trivial details like exact PNG encoding or whether the path can be relative, but nothing essential is missing for an agent to invoke it correctly.

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% and the schema already explains the 'path' parameter clearly. The tool description adds meaningful behavior beyond the schema: if path is provided it saves to disk; otherwise it returns base64. This conditional semantics is essential for correct invocation and is not stated in the schema.

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 action ('Take a screenshot'), a clear resource ('the visible area of the current tab'), and distinguishes itself from all siblings by being the only screenshot-related tool. It is unambiguous and immediately understandable.

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 description implies clear usage context: use when you need a visual capture of the current viewport. It explicitly limits scope to 'visible area', which tells the agent this is not a full-page capture. However, it does not name alternative tools or state when not to use it, but no direct alternative exists among siblings.

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