Get page structure

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

With no annotations provided, the description carries the behavioral burden, and it does well: it discloses shadow-piercing selector behavior, the conditional nature of the heading outline, and the top-frame/open-shadow-roots limitations. It does not describe the exact response shape or error behavior, but the key behavioral constraints are stated.

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 tightly scoped sentences: the first defines the resource and output elements, the second explains a conditional output detail, and the third states limitations. Every sentence earns its place with no filler or repetition of schema content.

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?

The description is sufficient for a simple read-only structure tool, especially given the 100% schema coverage for parameters. It explains the main content, selector behavior, conditional outline, and scope limits. The main gap is the lack of explicit return shape, but the enumerated output categories largely compensate.

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 of 3 applies. The description aligns with the include categories (regions, headings, lists, frames) but adds no parameter-level detail beyond what the schema already provides. It does not need to duplicate the schema's defaults.

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 opens with a specific verb and resource ('Reads the page structure') and enumerates exactly what is included: landmark regions, headings, nested lists, iframes, and shadow-piercing selectors. This is clear and non-generic, but it does not explicitly contrast the tool with siblings like get_page_snapshot, so it stops short of full 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 meaningful context: 'Top frame only, open shadow roots only' tells an agent when the tool's scope applies. However, it gives no explicit when-to-use or when-not-to-use guidance against sibling tools such as get_page_snapshot or run_a11y_audit, so alternatives are left to inference.

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