browser_take_screenshot

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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds transparency by stating that actions cannot be performed from the screenshot, reinforcing the read-only nature. It does not contradict annotations and provides behavioral context beyond what the structured data conveys.

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 consists of two concise sentences, with the core purpose in the first sentence and critical usage guidance in the second. It is front-loaded and contains no extraneous words, making it highly efficient.

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?

Given the tool has 6 parameters with full schema coverage and annotations providing safety hints, the description adds the key constraint about not being usable for actions and points to a sibling. It covers the most essential contextual information for an agent to decide when to use the tool, though it omits explicit mention of extra features like element or full-page screenshots (which are in the 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 description coverage is 100%, so the baseline is 3. The description does not elaborate on any parameter beyond the schema's own descriptions (e.g., type, scale, target, element, filename, fullPage). No additional meaning is added, so the score remains at the baseline.

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 clearly states the verb 'Take' and the resource 'screenshot of the current page', establishing the core function directly. It also explicitly distinguishes from the sibling tool 'browser_snapshot' by noting that this tool cannot be used for actions, which satisfies the requirement for sibling differentiation.

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 gives explicit guidance on when NOT to use this tool ('You can't perform actions based on the screenshot') and recommends the alternative 'browser_snapshot' for actions. This is clear context with exclusions, though it could additionally state use cases like visual debugging or archiving.

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