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?

Run evals on this skill

Adds up to 20 points to the overall score

View guide

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 13 hours ago

Table of Contents

Discovery Implementation Validation

Is this your skill?

If you maintain this skill, you can claim it as your own. Once claimed, you can manage eval scenarios, bundle related skills, attach documentation or rules, and ensure cross-agent compatibility.