mime-detection-routing

MIME type detection and extractor routing in core/mime.rs and core/extractor/bytes.rs — the extension→EXT_TO_MIME→validate→registry→extractor flow, key detection functions, the 115 case-insensitive extension map, priority-based registry selection, wildcard MIME families, and how to add a new MIME type. Load when adding a format, wiring an extractor to a MIME type, or debugging why a file routes to the wrong (or no) extractor.

Quality

83%

Does it follow best practices?

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Securityby

Passed

No findings from the security scan

Quality

Content

80%Weight 40%Scale 1-5

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

A tight, well-structured body that assumes Claude's competence and surfaces concrete functions and code. The main weakness is workflow clarity: routing changes lack explicit validation checkpoints despite the skill's own 'validate before extraction' rule.

Suggestions

Turn 'Adding New MIME Types' into a checked workflow: after step 3, add '4. Validate: call validate_mime_type() for the new MIME and confirm select_extractor_for_mime returns your extractor; only then proceed.'

Annotate the Key Functions table with file:line anchors (e.g. core/mime.rs:42) so the locations are directly actionable, not just file names.

Add a one-line 'Debugging a misroute' procedure (dump EXT_TO_MIME lookup → validate_mime_type → registry get_for_mime_type) so the trigger 'debugging why a file routes to the wrong extractor' has an executable workflow in the body.

Dimension	Reasoning	Score
Conciseness	Lean and efficient: every section is a compact table, code block, or numbered list with no padding or explanation of concepts Claude already knows; tokens earn their place.	5 / 5
Actionability	Provides concrete, executable guidance — a real Rust function signature and a numbered 'add a new MIME type' recipe — but the table's Location column points at files without line anchors and some steps (e.g. register_default_extractors) are named but not shown, leaving minor gaps.	4 / 5
Workflow Clarity	The detection flow is sequenced and the 'Adding New MIME Types' steps are listed, but a routing change is effectively a batch/destructive operation (files may route to the wrong extractor) and there are no validation checkpoints — e.g. 'validate_mime_type() before extraction' is stated as a rule but not embedded as a verify step in the workflow, which caps clarity at 3.	3 / 5
Progressive Disclosure	For a sub-50-line single-purpose skill with no bundle files, the body is a clear, well-organized overview with labeled sections and no nested references; structure is clean and easy to navigate.	5 / 5
	Total	17 / 20 Passed

Description

87%Weight 40%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

A strong, specific description that nails both the 'what' and the 'when' with concrete trigger phrases and a clearly bounded niche. It could add a few user-facing synonyms and file extensions to lift trigger coverage from good to comprehensive.

Dimension	Reasoning	Score
Specificity	Lists several specific capabilities — 'extension→EXT_TO_MIME→validate→registry→extractor flow', '115 case-insensitive extension map', 'priority-based registry selection', 'wildcard MIME families', and 'how to add a new MIME type' — with minor gaps (no mention of the infer-crate magic-number path here, though detect functions are named).	4 / 5
Completeness	Explicitly answers both what (the detection/routing flow and key functions) and when ('Load when adding a format, wiring an extractor to a MIME type, or debugging why a file routes to the wrong (or no) extractor') with concrete trigger phrases.	5 / 5
Trigger Term Quality	Good natural trigger coverage — 'Load when adding a format, wiring an extractor to a MIME type, or debugging why a file routes to the wrong (or no) extractor' — but lacks common synonyms and concrete file extensions a user might say (e.g. '.pdf', 'format detection', 'file type').	4 / 5
Distinctiveness Conflict Risk	It targets a precise niche (MIME detection and extractor routing in named core files) with triggers unlikely to fire for unrelated skills, so conflict risk is minimal.	5 / 5
	Total	18 / 20 Passed

Validation

100%

Warnings & errors only

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 16 / 16 Passed

Validation for skill structure

No warnings or errors.

Repository: xberg-io/xberg
Path: .ai-rulez/skills/mime-detection-routing/SKILL.md
Commit: 0a60357

Reviewed: about 12 hours ago

Table of Contents

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