fix(filesystem): return string in structuredContent to match outputSchema #3113
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…hema
The directory_tree, move_file, and list_directory_with_sizes tools were
returning an array in structuredContent.content, but outputSchema declares
content as z.string(). This caused MCP error -32602 validation failures.
Changed structuredContent from { content: [contentBlock] } to { content: text }
to match the declared outputSchema and be consistent with other filesystem
tools like list_directory and search_files.
Fixes modelcontextprotocol#3110, modelcontextprotocol#3106, modelcontextprotocol#3093
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <[email protected]>
…compliance Adds tests to verify that directory_tree, list_directory_with_sizes, and move_file tools return structuredContent.content as a string (matching outputSchema) rather than an array. These tests prevent regression of issues modelcontextprotocol#3110, modelcontextprotocol#3106, modelcontextprotocol#3093. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <[email protected]>
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Description
Fixes the
MCP error -32602: Output validation errorthat occurs when usingdirectory_tree,move_file, andlist_directory_with_sizestools.Root cause: These three tools were returning
structuredContent: { content: [contentBlock] }(array) but theiroutputSchemadeclares{ content: z.string() }. This mismatch caused schema validation to fail.Fix: Changed
structuredContentfrom{ content: [contentBlock] }to{ content: text }to match the declaredoutputSchema, consistent with other working tools likelist_directoryandsearch_files.Server Details
directory_tree,move_file,list_directory_with_sizes)Motivation and Context
Multiple users reported MCP error -32602 when calling these tools. The error message indicated:
This was because
structuredContent.contentwas an array of content blocks instead of a string as declared inoutputSchema.How Has This Been Tested?
directory_treetool in Claude Code - no validation errorlist_directory_with_sizestool in Claude Code - no validation errormove_filetool in Claude Code - no validation errorBreaking Changes
None. The
contentfield (array of content blocks) remains unchanged for backwards compatibility. OnlystructuredContentis fixed to match the declared schema.Types of changes
Checklist
Additional context
Fixes #3110, #3106, #3093
🤖 Generated with Claude Code