# Web Research > Answers factual questions by searching the web, fetching primary sources, and cross-checking claims before citing them. - Skill: `infinition/web-research` (Agent Skill) - Install (CLI): `npx skillmds@latest add infinition/web-research` - Raw SKILL.md: https://api.skillmd.com/api/skills/infinition/web-research/raw - Safety review: CAUTION (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Research & Search, Web Research - Tags: Citation, Cross Checking, Fact Checking, Primary Sources, Web Fetch, Web Search - Author: infinition (https://skillmd.com/u/infinition) - Updated: 2026-08-22 - Page: https://skillmd.com/skills/infinition/web-research --- # Web research The everyday case: the user asks something you cannot answer from what you know, and the answer must be TRUE today. Two or three well-chosen calls, a cross-check, an answer with its sources. For a multi-pass cited report on a broad subject, use `deep_research_synthesis` instead and call `research_mode` first. This skill is the fast, correct lookup. ## Choose the right tool, it decides everything | Tool | Takes | Returns | Use when | |---|---|---|---| | `web_search` | `query`, `num_results` | titles, URLs, snippets | you need to SEE what exists and pick | | `web_deep_search` | `query`, `num_results` | snippets AND the full text of the top results | you want the answer, not a list | | `web_fetch` | `url` (ONE, a string) | the clean text of that page | you already know the page that holds it | | `browser_navigate` | `url`, `wait_seconds` | a real rendered browser | the content needs JavaScript or a session | | `image_search` | `query`, `limit` | real image URLs | you need an illustration, instead of inventing a link | `web_deep_search` is the default for a real question. `web_search` alone returns snippets, and a snippet is an advertisement for a page, not evidence from it. Answering from snippets is the most common way to be confidently wrong. `web_search` also takes `allowed_domains` and `blocked_domains`, both arrays. Use `allowed_domains` to pin a search to a primary source (`["docs.rust-lang.org"]`) and `blocked_domains` to cut a content farm that keeps winning the ranking. **`read_extract` is not a web tool.** It takes `path`, a LOCAL file, and reads PDF, `.txt` or `.md`. Passing it a URL returns "File not found". The web equivalent is `web_fetch`, which already extracts a PDF served over HTTP. `read_extract` is for the file you have downloaded to disk: see the paragraph below. ## A PDF that `web_fetch` will not give you Some servers refuse a plain fetch of a PDF, or the document is behind a redirect chain. Download it, then read it from disk. ```bash curl -sL "https://example.com/paper.pdf" -o "C:\\tmp\\paper.pdf" ``` Then `read_extract` with `path` set to `C:\tmp\paper.pdf`. It returns the text, and for a long document a head and tail excerpt rather than a truncation with no warning. Use an absolute path: a relative one resolves against the server's working directory, not yours. ## Procedure 1. **Anchor the question in time.** Read the authoritative date at the end of your context. For anything current, put the year in the query. Your training prior is old and will quietly answer with a stale fact. 2. **Query like a document, not like a person.** Search engines match the words that appear on the target page. `laruche release notes 2026` beats `what is new in LaRuche this year`. Two or three distinct phrasings beat one repeated. 3. **Run the searches in PARALLEL.** They are read-only, so several calls travel in the same message. One angle per call. Sequential searching is the slowest possible way to do this. 4. **Open the pages that matter** with `web_fetch`. A long page is paginated: the output tells you the total size and the `offset` for the next chunk. If the answer is not in the first chunk, read on, do not guess. 5. **Record every decisive fact with `finding`, the moment you learn it**, with its URL. The findings ledger survives context compaction. A fact you did not record can be gone before you write the final answer. 6. **Cross-check anything that matters.** Two independent sources, not two pages copying the same press release. A number, a date, a price or a claim about a person needs a second source. If the sources disagree, say so instead of picking one. 7. **Answer with the sources**, and state plainly what you could not establish. ## Prefer the primary source Official documentation, the project repository, the standards body, the company's own announcement. A blog summarising a release is one telephone game away from the truth and is usually months behind. When a page cites a source, go and read that source. ## Traps - **The snippet trap.** Deciding from search snippets alone. Open the page. - **The stale answer.** Answering from memory on a question that has a current answer. Anything with "latest", "current", "now", "this year" or a price in it must be searched. - **The single source.** One page saying something is a claim, not a fact. - **Content farms and AI slop.** A page with no author, no date, and text that restates the question is worthless. Prefer a dated page with a named author. - **The paginated page.** Reading the first 12000 characters and concluding the answer is absent. Check the size hint and continue with `offset`. - **Fabricating a URL.** Never write a link you have not fetched. If you need an image, use `image_search`; do not invent image URLs. ## Failure modes **403, paywall, captcha, or an empty result.** An obstacle, never a conclusion. In order: try `web_fetch` with `render: true`, then the Wayback Machine (`https://web.archive.org/web/2026/`), then a search-engine cache, then a mirror, then another source entirely. Only after all of those do you report the angle as blocked. **The search returns nothing useful.** The query is phrased as a question, or uses your vocabulary rather than the page's. Rewrite it with the words that would literally appear on the page you want. Try the domain's own terminology. **Every result is the same article, syndicated.** You found a press release. Search for the primary source it is based on: the paper, the filing, the repository, the official post. **The page loads but is empty.** It is JavaScript-rendered. `web_fetch` with `render: true`, and if that still fails, `browser_navigate`. **You cannot establish the fact.** Say so, name what you tried, and give the closest thing you did establish. A clear "I could not confirm this" is a correct answer. An invented one is not.