Add x-ms-usermessage header to MCP tools/call requests

[akashjindal123]

Summary

• Adds x-ms-usermessage HTTP header to MCP tools/call requests, passing the user's original message to MCP servers during tool execution
• Implements ASCII-safe sanitization in Utility.sanitizeTextForHeader(), matching the .NET HttpContextHeadersHandler.SanitizeTextForHeader() implementation (diacritics removal, smart punctuation conversion, non-breaking space normalization, whitespace collapsing)
• Centralized in Utility.GetToolRequestHeaders() — zero changes needed in Claude, OpenAI, or LangChain extension packages

Test plan

• pnpm build — clean compilation across all packages
• pnpm test — all 1061 tests pass (56 suites)
• New tests cover: header presence/absence, diacritics stripping, smart quote conversion, non-ASCII replacement, whitespace collapsing, coexistence with other headers

🤖 Generated with Claude Code

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[Copilot]

Pull request overview

This PR adds propagation of the user’s original message to MCP-related HTTP requests via a new x-ms-usermessage header, with ASCII-safe sanitization to make the value safe for transport as an HTTP header.

Changes:

• Add x-ms-usermessage header generation to Utility.GetToolRequestHeaders().
• Implement Utility.sanitizeTextForHeader() to normalize/sanitize user text for header safety.
• Add Jest coverage validating header presence/absence and sanitization behaviors.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
tests/tooling/utility.test.ts	Adds unit tests covering x-ms-usermessage header behavior and sanitization outcomes.
packages/agents-a365-tooling/src/Utility.ts	Adds the new header constant, wires header injection into GetToolRequestHeaders(), and introduces sanitization helper.

[Copilot]

GetToolRequestHeaders sets x-ms-usermessage whenever activity.text is truthy, but sanitizeTextForHeader() can return an empty string (e.g., whitespace-only input or strings that sanitize down to nothing). This will send an empty header value; instead, compute the sanitized value first and only add the header when the sanitized result is non-empty.

Suggested change

	headers[Utility.HEADER_USER_MESSAGE] = Utility.sanitizeTextForHeader(userMessage);
	const sanitizedUserMessage = Utility.sanitizeTextForHeader(userMessage);
	if (sanitizedUserMessage) {
	headers[Utility.HEADER_USER_MESSAGE] = sanitizedUserMessage;
	}

[Copilot]

The catch clause in sanitizeTextForHeader() returns the original input, which can violate the method’s own contract/documentation (“ASCII-safe text suitable for HTTP header values”). If an error occurs, prefer returning a conservative sanitized fallback (e.g., strip/replace non-ASCII/control chars and collapse whitespace) or omit the header entirely, rather than returning unsanitized text.

Suggested change

	return input;
	// Conservative fallback: avoid returning unsanitized text if normalization fails.
	return input
	.replace(/[\u00A0\u202F]/g, ' ')
	.replace(/[^\x20-\x7E]/g, ' ')
	.replace(/\s+/g, ' ')
	.trim();

[Copilot]

PR description says the header is added to MCP tools/call requests, but this implementation adds x-ms-usermessage for any request that uses Utility.GetToolRequestHeaders() (including tooling gateway discovery and chat history calls). If the intent is truly scoped to tool execution, consider gating this behind an explicit ToolOptions flag (or a dedicated header builder for tool calls) or update the PR description to reflect the broader behavior.