---
description: "MCP and web-tool guidance: current-doc retrieval, direct-tool preference, MCP Apps structured content, and version-aware external lookups."
alwaysApply: false
---

# MCP and Web Tools

Use this rule when current documentation, external systems, or plugin-backed tools matter.

## Preferred Order

When multiple paths exist, prefer:

1. direct native tools exposed in the prompt
2. direct plugin or MCP-backed tools exposed in the prompt
3. MCP resource functions when available
4. MCP Apps structured content when returned by a tool
5. `WebSearch` and `WebFetch`

Do not assume old wrapper APIs are present just because they appear in older docs or rules.

## Web Search Discipline

Use `WebSearch` for:
- package versions
- breaking changes
- compatibility questions
- recent framework behavior
- error messages after repeated failures

Use `WebFetch` for:
- official docs pages
- changelogs
- reference pages that need close reading

Before presenting advice as `current`, `official`, `recommended`, or `best practice`, verify it against a current authoritative source such as official docs, release notes, or changelogs.

When versions matter:
- use the actual current month and year
- do not leave placeholders in the search query
- do not rely on stale memory when a current source is available

## MCP Discipline

- Follow the exact schema of currently exposed tools.
- If the environment exposes direct tools, use them directly.
- If the environment exposes resources instead of actions, use the resource discovery and fetch path.
- If a tool returns MCP Apps structured content, use the structured form rather than the prose form.
- Keep assumptions about server names and tool IDs out of general rules.

## Typical Chains

```text
Version check -> install or configure -> verify
Docs lookup -> implement -> behavior check
Resource discovery -> targeted fetch -> synthesize
Visual diff -> grounded report
```

For version-sensitive setup guidance, prefer:

```text
Current authoritative source -> install or configure -> executable verification
```

## Failure Handling

If an MCP or plugin call fails:
- re-check the current schema
- simplify the arguments
- remove stale placeholder text
- fall back to another available source if the integration is optional
- if the tool returned structured content, check whether the prose view missed a useful field