browser_screenshot

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds use-case context but does not disclose the return format (image bytes vs. URL) or any capture limits, which is a meaningful omission for a screenshot 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?

Two tight sentences with no filler; the action is front-loaded and the routing condition follows immediately. Every clause 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 3-parameter read-only tool with full schema coverage and annotations, the description covers purpose and usage adequately. The main remaining gap is the absence of any note on what the tool returns, which matters more here because there is no output schema.

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%, so selector, full_page, and session_id are fully documented in the schema. The description's phrase 'current page or a specific element' only loosely maps to those parameters and adds no syntax or default details, so the baseline 3 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?

States a specific verb and resource ('Take a screenshot') with explicit scope ('current page or a specific element'). It also names the sibling alternative (accessibility tree), so an agent can distinguish it from browser_get_accessibility_tree and browser_get_html without opening schemas.

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?

Gives a clear condition for use ('visual verification') and an explicit alternative trigger ('when the accessibility tree is not sufficient'). It stops short of stating when not to use it (e.g., prefer text extraction for simple content), but the routing guidance is solid.

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