fetch_page

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

With no annotations provided, the description carries the full disclosure burden and does it well: it details auth mode (Safari cookies default, private for anonymous), pagination behavior with start_char, deterministic hashing, and that backend selection is never silent. It even discloses truncation tail markers. Minor gap: no explicit statement of destructive/side-effect behavior (e.g., whether fetching stores data permanently), but overall disclosure is strong.

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 five dense paragraphs covering substantial complexity (headless rendering, shape classification, determinism, auth, pagination, backend fallback). It front-loads the core purpose in the first sentence, then layers detail. A little tabular or bulleted structure for params and backend options would improve scannability, but given the complexity, the prose is appropriately economical.

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?

This is a complex, 7-parameter tool with no annotations and 0% schema coverage, yet the description covers rendering semantics, determinism, auth modes, pagination, shape behavior, and backend selection. An output schema exists (documenting return values), so the description needn't explain them. The main residual gaps are the exact list of valid backend values and a systematic param-by-param mapping, but for the complexity level it's remarkably complete.

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 must compensate, and it does for several params: private (anonymous fetch vs Safari cookies), wait_selector (SPA late-paint handling), start_char (pagination slicing), backend and allow_external_fallback (backend selection). However, url, max_chars, and the specific syntax/format of backend values (native/opencli/twitter-cli) aren't documented in a systematic way. Coverage is good but not exhaustive given 7 params.

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, vivid purpose: 'Fetch a web page as clean, deterministic markdown with provenance.' It distinguishes itself from siblings by detailing headless-browser rendering, shape classification, YAML front-matter, and hash-based determinism. This clearly differentiates it from archive_search, fetch_archived, download_video, and page_links.

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 provides explicit when-to-use guidance: private=true for anonymous fetches, wait_selector only for late-painting SPAs, and clear notes on feed vs article page shapes. It also explains backend fallback behavior when native capture is gated on a covered URL, directing users to backend='opencli'/'twitter-cli' or allow_external_fallback=true. This is strong alternative-and-condition guidance.

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