Outline of a PDF

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

Annotations already declare the safe read-only, idempotent, closed-world profile, so the bar is lower. The description still adds real value by disclosing the heuristic source of the outline ('from bookmarks or detected headings'), warning the agent that results may fall back to inferred headings rather than authoritative bookmarks.

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?

A single compact sentence that front-loads the resource and then the output form and contents. No filler; slightly dense but nothing wasted.

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?

An output schema exists, so the description need not explain the tree structure, and annotations cover the safety profile. What remains — the input path convention and format choice — is covered between the schema and the description, leaving only sibling differentiation unaddressed.

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 coverage is 50%: 'input' is documented in the schema but 'format' is not. The description compensates by enumerating the two output forms (Markdown list or JSON tree), which maps to the format enum, so it covers the gap adequately without adding syntax detail.

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 names the concrete resource (the document's outline) and specifies both the source (bookmarks or detected headings) and the return shape (Markdown list or JSON tree with page ranges). It is clear and specific, though it does not explicitly distinguish itself from the adjacent pdf_extract_structure sibling, which an agent might plausibly confuse with an outline.

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 when-to-use guidance, no prerequisites, and no named alternative. With 30 siblings in the family, the absence of any routing hint (e.g., 'use pdf_info for metadata, this for the hierarchy') leaves the agent to infer selection entirely.

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