Cursor is only as useful as the context you give it. More context is not automatically better. The goal is relevant context: the files, constraints, examples, and tools that change the answer.

Context Sources

Cursor can draw from several places:

• Open files, selected code, and recently edited files.
• Mentioned files, folders, symbols, images, and documentation.
• Semantic repository search.
• Project Rules, User Rules, Team Rules, and AGENTS.md.
• Skills in .cursor/skills, .agents/skills, .claude/skills, or .codex/skills.
• Memories that capture reusable preferences.
• MCP servers that expose external data and tools.
• Web search and fetched pages when allowed.

The agent will often find the obvious files itself. You should still name the files that define correctness.

Tell Cursor What Matters

Use a short context contract at the top of bigger prompts:

Relevant context:
- The public API is in @src/lib/server/invitations.ts.
- Existing validation tests are in @src/lib/server/invitations.test.ts.
- Follow @.cursor/rules/testing.mdc.

Goal:
Reject expired invite tokens with the same error shape used by revoked tokens.

This does two things. It saves search time, and it tells the model what evidence you expect it to respect.

Rules, Skills, and Markdown References

Use the smallest durable container that fits the job:

• Use Rules for behavior that should apply automatically.
• Use Skills for reusable workflows with instructions, scripts, references, or assets.
• Use ordinary Markdown files for longer explanations that a human should review and version.
• Use Memories for preferences that are useful across sessions but do not belong in source control.

Do not hide architectural truth in chat history. If a future contributor needs it, put it in the repository.

Avoid Context Rot

Stale context is worse than missing context because it sounds authoritative. When Cursor makes the same mistake twice, fix the durable instruction source instead of writing a longer prompt. When a rule or skill no longer matches the codebase, delete or update it in the same change that updates the code.

For code review prompts, ask Cursor to cite the files it inspected. If the answer does not mention the file that defines the behavior, the context set is not good enough yet.