tools-only Accessing Online Resources: Definitive Guide
Objective: Ensure high-fidelity data retrieval for technical tasks by selecting the correct tool.
Tool Selection Matrix
| Tool | Fidelity | Purpose | Use When... |
|---|---|---|---|
| WebFetch | Low (Summarized) | Scoping & Overview | You need to know what something is or get a high-level summary. NEVER use for technical implementation details. |
| Exa | Medium (Markdown) | Content Extraction | You need to read documentation, see code snippets, or extract specific content from a page. |
| Ref | High (Detailed) | Deep Reading | You need authoritative, verbatim documentation or deep technical specs. |
Experimental Evidence
We benchmarked these tools against three targets: Anthropic Docs, GitHub, and PyPI.
1. WebFetch (The "Summarizer")
- Behavior: Aggressively summarizes content. Converts HTML to a high-level overview.
- Data Loss: Strips file lists, specific code comments, and detailed syntax.
- Risk: High risk of hallucination if asked for details it filtered out (e.g., "commit messages" in a file list).
- Example Output:
"The repository contains 6 essential slash commands... Design Philosophy: The collection intentionally limits itself..." (Missing: Actual file list, specific code, installation nuances)
2. Exa (The "Extractor")
Behavior: Returns Markdown-formatted content extracted from the HTML.
Data Retention: Preserves code blocks, tables, and structure.
Example Output:
"├──yaml_optimizer.py # YAML anchor/alias optimization" (Visible: File tree, comments, code blocks)
3. Ref (The "Reader")
- Behavior: High-fidelity retrieval, often verbatim.
- Data Retention: Maximum. Preserves exact syntax, version numbers, and directives.
- Example Output:
Detailed, verbatim documentation suitable for deep technical analysis.
Critical Rules
- NEVER use
WebFetchfor "How-To": If you need to know how to implement something,WebFetchwill fail you. It will give you a summary of the concept, not the code. - ALWAYS use
ExaorReffor Code: If you need to see file structures, specific comments, or configuration options, you must use a high-fidelity tool. - Verify, Don't Infer: If a tool returns a summary, do not guess at the missing details. Switch to a higher-fidelity tool.