Get document outline (heading TOC)

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

With no annotations provided, the description fully discloses key behaviors: the server never fetches any external resources, 'html' is the sole data source, and 'url' is only used for origin context and absolutizing links. It also notes the absence of transformations like Readability or Turndown. This provides a comprehensive behavioral picture.

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 is extremely concise: two sentences that front-load the purpose and then quickly detail behavioral constraints. No superfluous words; every sentence adds unique value. The structure is efficient and easy to parse.

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's simplicity (2 parameters, 1 required, output schema present), the description covers all necessary aspects: purpose, usage context, behavioral traits, parameter roles, and relationship to siblings. It is fully sufficient for an AI agent to select and invoke the tool correctly.

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 input schema covers both parameters with descriptions (100% coverage), meeting the baseline of 3. The description adds significant context beyond the schema: 'url' is 'NEVER fetched — origin context only', and 'html' is already-rendered and used unmodified. This additional semantic clarity justifies a score of 4.

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 tool's function: returning a document outline (h1-h6 headings with stable anchor ids) from already-rendered HTML. It distinguishes itself from siblings by emphasizing it is a 'pure heading walk' with no Readability, Turndown, or sanitization, making the purpose specific and non-ambiguous.

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 positions the tool as a 'cheap pre-check before full extraction', implying it should be used when only headings are needed. It contrasts with extraction tools by listing what it omits (Readability, Turndown, sanitization). However, it does not explicitly name sibling tools or state when not to use it, but the context is clear enough.

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