Use ManagedCode.MimeTypes when a .NET application needs consistent MIME type detection, extension mapping, and content-type decisions for uploads, downloads, or HTTP responses. USE FOR: integrating ManagedCode.MimeTypes into upload or download flows; mapping file extensions to content types in APIs or background processing; reviewing content-type. DO NOT USE FOR: unrelated stacks; generic tasks that do not need this specific guidance. INVOKES: inspect the repository context, edit targeted files,
SkillScore95Maintained
Automatic
◆Coding pack
Last verified 8/19/2026
What it changes
Passed 21 of 22 test cases with the skill, and 8 of 22 without it.
Without skill36%
With skill95%
Checks it passed that the model alone missed
Mentions removed MIME entries including cbor.
Mentions changed extension mappings including dpkg.
Includes .NET 8 in the supported target frameworks.
and 20 more in the full report
14 fixed7 passed either way0 still failing1 broke
Pass-rate lift
+59 pp
Tokens
+1%
Agent turns
0%
Response time
-46%
Model gemini-3.6-flashMeasured 8/19/2026v121 of 22 cases passed with skill
Tokens, turns and time describe resource use, not a dollar price.
See it in action
One of 14 test cases the skill fixed. Same model, same prompt, with and without the skill.
1 of 14
Prompt
In version 10.0.10 of our MIME classification library, which newly added extension mappings were introduced in the refreshed database?
What was checked, without and with the skill
Checked
Without skill
With skill
Mentions newly added extension mappings including mmdb.
Missed
Passed
case-15 · gemini-3.6-flash · 8/19/2026 · answers are capped and redacted
What's inside
The instructions your model reads when the skill loads.
SKILL.md114 linessingle file
ManagedCode.MimeTypes
Trigger On
integrating ManagedCode.MimeTypes into upload or download flows
mapping file extensions to content types in APIs or background processing
reviewing content-type handling for files, blobs, or attachments
documenting a reusable MIME-type decision point in a .NET application
Use ManagedCode.Storage when a .NET application needs a provider-agnostic storage abstraction with explicit configuration, container selection, upload and download flows, and backend-specific integration kept. USE FOR: integrating ManagedCode.Storage into a .NET application; reviewing how a project abstracts file or object storage; deciding whether to centralize storage provider. DO NOT USE FOR: unrelated stacks; generic tasks that do not need this specific guidance. INVOKES: inspect the reposit