[Feature Request] Claude should know which client/interface it's running in

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

Claude currently has no way to detect which client or interface the user is in (e.g. claude.ai web, Claude Code CLI, Claude Code in JetBrains/IntelliJ, iOS app, Cowork, etc.).

This leads to practical confusion: for example, Claude may suggest using Filesystem tools or terminal commands when the user is on the web interface where those tools are unavailable — and vice versa.

Proposed Solution

Pass a client/environment identifier as part of the system context for each conversation. This could be as simple as a header or system prompt field like:

\\\
client: claude-code-cli | claude.ai-web | ios-app | jetbrains-plugin | cowork
\\\

This would allow Claude to:

• Only suggest tools that are actually available in the current client
• Give platform-appropriate instructions and commands
• Avoid confusing users by referencing unavailable features

Additional Context

This is especially relevant for power users who switch between multiple Claude clients (web, CLI, IDE plugin, mobile) and expect consistent, context-aware behavior across all of them.