Capture page

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

Annotations already declare readOnlyHint, openWorldHint, and destructiveHint. The description adds meaningful behavioral context by warning that images can contain visible page data and clarifying that full-page capture requires explicit request. This goes beyond the annotations without contradicting them.

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?

Three sentences with no filler: core behavior is front-loaded, the privacy warning is valuable, and the return type is stated. Every sentence 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 simple two-parameter capture tool with no output schema, the description covers the key operational details: default scope, full-page opt-in, output type, and data-visibility risk. It lacks an explicit comparison to tab_snapshot and precise output encoding, but it is otherwise sufficient.

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 schema documents session_id but leaves full_page with only a type. The description compensates partially by indicating that full-page capture happens only when explicitly requested, implying the default is viewport-only. However, it does not name the parameter or explain its format beyond that implication.

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 names the action ('Capture') and the resource ('current viewport' or 'full page'), and states the output ('image and URL metadata'). It is specific enough to distinguish it from status/navigation tools, though it does not explicitly differentiate it from the similarly named sibling tab_snapshot.

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?

There is no guidance on when to choose this tool over tab_snapshot, tab_extract, or other siblings, and no exclusions or alternative routing. The 'when explicitly requested' note is about the full_page parameter, not about tool selection, so it does not satisfy the usage-guideline dimension.

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