browser_screenshot

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

With no annotations, the description carries the full burden. It conveys that the operation is non-mutating ('capture'), scopes it to the current viewport rather than the full page, and specifies the JPEG output format. It does not disclose resolution or encoding details, but for a zero-parameter read-only tool this is adequate.

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?

A single, front-loaded sentence with no filler. Every word adds meaning: capture (action), current viewport (scope), JPEG (format).

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 zero-parameter action with no output schema, the description covers the essential operational facts: what is captured, from where, and in what format. It omits minor details like image dimensions or return mechanism, but nothing critical is missing for invoking the tool 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?

There are no parameters, so the schema is trivially complete and the description need not explain any inputs. The baseline of 4 for zero-parameter tools applies.

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 names a specific verb ('capture'), a precise target ('current viewport'), and an output format ('JPEG'). This distinguishes it from action-oriented siblings like browser_click or browser_type, and from observation tools, because none claim to produce a screenshot.

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?

No guidance is given about when a screenshot should be preferred over browser_observe or browser_extract, nor any exclusion criteria. The description simply states what it does, leaving the agent to infer when to use it.

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