Cursor rule

1---
2description: "MCP and web-tool guidance: current-doc retrieval, direct-tool preference, MCP Apps structured content, and version-aware external lookups."
3alwaysApply: false
4---
5 
6# MCP and Web Tools
7 
8Use this rule when current documentation, external systems, or plugin-backed tools matter.
9 
10## Preferred Order
11 
12When multiple paths exist, prefer:
13 
141. direct native tools exposed in the prompt
152. direct plugin or MCP-backed tools exposed in the prompt
163. MCP resource functions when available
174. MCP Apps structured content when returned by a tool
185. `WebSearch` and `WebFetch`
19 
20Do not assume old wrapper APIs are present just because they appear in older docs or rules.
21 
22## Web Search Discipline
23 
24Use `WebSearch` for:
25- package versions
26- breaking changes
27- compatibility questions
28- recent framework behavior
29- error messages after repeated failures
30 
31Use `WebFetch` for:
32- official docs pages
33- changelogs
34- reference pages that need close reading
35 
36Before presenting advice as `current`, `official`, `recommended`, or `best practice`, verify it against a current authoritative source such as official docs, release notes, or changelogs.
37 
38When versions matter:
39- use the actual current month and year
40- do not leave placeholders in the search query
41- do not rely on stale memory when a current source is available
42 
43## MCP Discipline
44 
45- Follow the exact schema of currently exposed tools.
46- If the environment exposes direct tools, use them directly.
47- If the environment exposes resources instead of actions, use the resource discovery and fetch path.
48- If a tool returns MCP Apps structured content, use the structured form rather than the prose form.
49- Keep assumptions about server names and tool IDs out of general rules.
50 
51## Typical Chains
52 
53```text
54Version check -> install or configure -> verify
55Docs lookup -> implement -> behavior check
56Resource discovery -> targeted fetch -> synthesize
57Visual diff -> grounded report
58```
59 
60For version-sensitive setup guidance, prefer:
61 
62```text
63Current authoritative source -> install or configure -> executable verification
64```
65 
66## Failure Handling
67 
68If an MCP or plugin call fails:
69- re-check the current schema
70- simplify the arguments
71- remove stale placeholder text
72- fall back to another available source if the integration is optional
73- if the tool returned structured content, check whether the prose view missed a useful field
74