[tsarlandie-oai]

Motivation and context

Skill::validate compares a URI segment with the UTF-8 name from SKILL.md frontmatter. A skill named café therefore fails validation with NameMismatch when a server advertises skill://caf%C3%A9/SKILL.md. This came up while reviewing the filesystem catalog in #1409 and also affects servers that construct their own entries.

Percent-decode the name segment once and compare it with the frontmatter using the NFKC form used by the Agent Skills reference validator. Enforce the 1–64 character limit and allow lowercase letters, letters from scripts without case, numbers, and single internal hyphens. Invalid names now produce a distinct validation error. Agent Skills naming rules

When checking a listing for duplicate entries, use the same percent-encoding normalization as the manifest checker. This catches equivalent spellings of a skill URI while preserving the advertised URI for reads.

Tests

• Reproduced NameMismatch on main with the new Unicode regression test. The fix accepts top-level and nested names with either hex case. Tests also cover invalid UTF-8, double encoding, and an encoded slash.
• A list containing equivalent URI spellings now returns DuplicateSkill. The regression test covers the hex case, an escaped unreserved character, and a literal Unicode name.
• Tests cover the 64/65-character boundary, uncased scripts, invalid name syntax, and composed and decomposed Unicode spellings. cargo test -p rmcp --lib --no-default-features passed all 193 tests.
• cargo test -p rmcp --features client --test test_skills passed all 14 tests.
• cargo clippy -p rmcp --lib --no-default-features -- -D warnings and cargo +nightly fmt --all -- --check passed.
• Tested locally together with the filesystem catalog from feat: load skills from a directory tree #1409 and its follow-up fix(skills): prevent symlink swaps during catalog loads #1438. All 30 catalog tests passed. A separate test verified that a real café/SKILL.md appears under the encoded URI and returns the original Markdown through read_resource.

[chatgpt-codex-connector]

Codex Review Summary: ✅ Completed

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-11-07T06:05:06.645957Z	793e02a	New commits

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[github-actions]

@jamadeo is on triage rotation this week and is the reviewer for this one.

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[chatgpt-codex-connector]

💡 Codex Review

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Reviewed commit: 94982693ab

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[DaleSeo]

Thanks for chasing this down, @tsarlandie-oai!