Set default content to an empty array instead of nil#150
Merged
koic merged 1 commit intomodelcontextprotocol:mainfrom Oct 3, 2025
Merged
Conversation
atesgoral
previously approved these changes
Oct 2, 2025
juharris
reviewed
Oct 2, 2025
lib/mcp/tool/response.rb
Outdated
Contributor
There was a problem hiding this comment.
Should we instead handle when nil is passed to this method?
Suggested change
| @content = content || [] |
Member
Author
There was a problem hiding this comment.
Yeah, that makes sense! I've added test code for that case and updated this PR.
Follow-up to modelcontextprotocol#147. According to the specification schema, `content` is not optional and therefore cannot be omitted: ```typescript interface CallToolResult { _meta?: { [key: string]: unknown }; content: ContentBlock[]; isError?: boolean; structuredContent?: { [key: string]: unknown }; [key: string]: unknown; } ``` https://modelcontextprotocol.io/specification/2025-06-18/schema#calltoolresult Instead of `nil`, an empty array is set as the default value. There may be a better value for `content`, but at the very least it should not be missing.
koic
force-pushed
the
set_default_content_to_an_empty_array_instead_of_nil
branch
from
1f614c2 to
0034952
Compare
juharris
approved these changes
Oct 2, 2025
atesgoral
approved these changes
Oct 3, 2025
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Motivation and Context
Follow-up to #147.
According to the specification schema,
contentis not optional and therefore cannot be omitted:https://modelcontextprotocol.io/specification/2025-06-18/schema#calltoolresult
Instead of
nil, an empty array is set as the default value.There may be a better value for
content, but at the very least it should not be missing.How Has This Been Tested?
The related test code has been updated.
Breaking Changes
#147 is unreleased, there are no breaking changes on the main branch.
Types of changes
Checklist