outline

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

Behavior is disclosed well beyond the read-only/idempotent annotations: it describes document-order capping at limit, per-entry fields, and the fallback to the whole body when a selector matches nothing while still echoing the requested selector. No contradiction with annotations.

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 core purpose is front-loaded in the first clause, then the description adds required detail in a compact, information-dense sequence without repeating schema defaults or annotation data. Every sentence contributes either return semantics, fallback behavior, or usage routing.

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 relatively simple read-only outline tool with two optional parameters, the description covers input semantics, output shape, edge behavior, and when to prefer it over siblings. The output schema exists, so the listed return fields are a bonus rather than a burden, and nothing necessary for a correct call is missing.

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 0%, so the description carries the full burden, and it delivers: selector and limit are both explained with defaults and behavior, including the no-match fallback for selector and the 200 cap for limit. An agent can fill both parameters correctly without needing extra documentation.

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 precise definition: 'Structural outline of a page or region: the shape an agent can act on, without a screenshot.' It names the exact output shape and explicitly contrasts itself with sibling tools (page_state, styles, screenshot), so an agent can tell which tool to use from the description alone.

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?

It says 'Use it before editing a region or diffing a mockup against the app' and then names alternatives: 'page_state is the clickable list, styles the computed CSS, screenshot for humans.' This is explicit when-to-use guidance with sibling differentiation and no ambiguity.

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