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aws-lambda-managed-instances

Evaluates, configures, and migrates workloads to AWS Lambda Managed Instances (LMI). Runs Lambda Event Functions (standard Lambda) on EC2 instances in the user's account while AWS manages provisioning, patching, scaling, routing, and load balancing. Triggers when queries mention Lambda Managed Instances, LMI, capacity providers, multi-concurrent execution environments, EC2-backed Lambda, persistent Lambda instances, PerExecutionEnvironmentMaxConcurrency, CapacityProviderConfig, cold start elimination via dedicated instances, SOCI (Seekable OCI) image lazy loading, migrating Lambda Event Functions to managed instances, or cost comparison between Lambda Event Functions and LMI with Savings Plans or Reserved Instances. Also covers long-running and asynchronous workloads and the 90-minute (5400s) function timeout for asynchronous and event-source-mapping (SQS, Kinesis, DynamoDB Streams / ESM) invocations, including how to raise the function timeout up to 90 minutes / 5400s and the related duration limits.

Quality

85%

Does it follow best practices?

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SecuritybySnyk

Passed

No findings from the security scan

SKILL.md
Quality
Evals
Security

Quality

Content

75%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 well-engineered skill body: table-driven, fact-dense, with a clear six-step workflow, explicit validation and cutover gating, and an exemplary reference routing structure that is one level deep and matches the actual bundle. The remaining gaps are moderate — repeated key facts that cost tokens, deferred executable command sequences, no explicit rollback path during cutover, and an orphaned assets/sqs-processor/template.yaml that no file links to.

Suggestions

Consolidate the repeated 90-minute/5400s timeout and 3-minimum-execution-environments facts into their primary sections plus the limits table, and replace the other recurrences with a short pointer to those sections to reclaim tokens.

Link the assets/sqs-processor/template.yaml example from SKILL.md (e.g., in the Files table or the infrastructure row of the routing table) so the bundle's ready-made template is discoverable.

Add an explicit rollback/abort checkpoint to Step 6 (e.g., 'if throttle rate exceeds 1% or costs regress during the shift, revert traffic to the Lambda Event Function and consult troubleshooting.md').

DimensionReasoningScore

Conciseness

The body is dense and factual — decision tables, numeric limits, pricing components — with no padding explaining concepts Claude already knows; the SOCI and 90-minute-timeout detail is genuinely non-obvious knowledge that earns its tokens. Not 5: several key facts are repeated across sections (the 5400s/90-min timeout appears in the decision table, Step 1, Step 3, the long-duration section, and the limits table; the 3-environment minimum and 'set MaxVCpuCount explicitly' each recur ~4 times), which could be consolidated; not 3: the repetition is deliberate emphasis, not unnecessary explanation.

4 / 5

Actionability

Guidance is concrete and executable: a specific CLI command ("update-function-configuration --timeout 5400"), SAM/CFN property ("Timeout: 5400"), exact memory-to-vCPU ratios, per-runtime concurrency caps, pricing math ("EC2 instance hours + 15% management fee + $0.20/1M requests"), alarm thresholds ("throttle rate > 1% and CPU > 80%"), and a staged cutover ("10% → 50% → 100%"). Not 5: complete command sequences and templates are deferred to reference files rather than given inline, so the body alone is not copy-paste complete for the common setup cases; not 3: what is present is specific and executable, not pseudocode.

4 / 5

Workflow Clarity

The six-step workflow (Assess → Cost comparison → Configure → Migrate → Infrastructure → Validate and cut over) is clearly sequenced, with a Step 1 signal-gathering checklist and explicit validation in Step 6 ("Deploy to a non-production environment first", monitor CloudWatch, gradual 10→50→100% shift, "Decommission ... once stable") plus inline error-recovery facts (stuck CREATING → missing NAT route). Not 5: there is no explicit rollback/abort path if throttling or cost regression appears mid-cutover — the recovery loop lives in troubleshooting.md rather than the workflow; not 3: validation checkpoints are explicit and present at the right points.

4 / 5

Progressive Disclosure

Structure is strong: a routing table instructing "Read ONLY the single reference file that matches the user's task", six real one-level-deep reference files (verified on disk, none nested), a Files index with content summaries, and key facts kept inline for always-mention use. Not 5: the bundle contains assets/sqs-processor/template.yaml which is never mentioned in SKILL.md or any reference — an orphaned asset that is invisible to navigation; not 3: content split, signaling, and depth are otherwise exactly right.

4 / 5

Total

16

/

20

Passed

Description

91%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 description that explicitly states what the skill does and when to trigger it, with an unusually thorough and well-chosen set of trigger terms including acronyms, API parameter names, and use-case phrasings. The main weaknesses are broad leading verbs and a few general Lambda terms that slightly widen conflict risk; it is also on the long side, though the length is spent on trigger coverage rather than fluff.

DimensionReasoningScore

Specificity

The description lists several concrete actions — "Evaluates, configures, and migrates workloads to AWS Lambda Managed Instances (LMI)" — plus a specific capability statement ("Runs Lambda Event Functions (standard Lambda) on EC2 instances in the user's account while AWS manages provisioning, patching, scaling, routing, and load balancing") in third-person voice. Not 5: the leading verbs are broad ("evaluates", "configures", "migrates") rather than the granular, comprehensive action list of the top anchor; not 3: well more than 1–2 actions with concrete domain detail.

4 / 5

Completeness

Both questions are answered explicitly: what ("Evaluates, configures, and migrates workloads to AWS Lambda Managed Instances... Runs Lambda Event Functions on EC2 instances...") and when ("Triggers when queries mention Lambda Managed Instances, LMI, ... or cost comparison...") with concrete trigger phrases. This mirrors the 5 anchor's structure exactly; 4 would require the 'when' to be less explicit than the enumerated trigger list given here.

5 / 5

Trigger Term Quality

Trigger coverage is comprehensive with synonyms and both user-natural and API-level terms: "Lambda Managed Instances, LMI, capacity providers, multi-concurrent execution environments, EC2-backed Lambda, persistent Lambda instances, PerExecutionEnvironmentMaxConcurrency, CapacityProviderConfig, cold start elimination via dedicated instances, SOCI (Seekable OCI) image lazy loading", plus use-case phrasings like "cost comparison between Lambda Event Functions and LMI with Savings Plans or Reserved Instances" and "raise the function timeout up to 90 minutes / 5400s". Matches the 5 anchor (full name + acronym synonyms, natural phrasings); a 4 would require noticeable missing natural terms, which are not evident.

5 / 5

Distinctiveness Conflict Risk

The core niche is clear with highly distinct triggers ("Lambda Managed Instances", "LMI", "PerExecutionEnvironmentMaxConcurrency", "CapacityProviderConfig", "SOCI"), so it is mostly distinct with only minor overlap risk. Not 5: broader Lambda-domain phrases like "long-running and asynchronous workloads", "cold start elimination", and "SQS, Kinesis, DynamoDB Streams / ESM" invocations could also pull queries intended for a general AWS Lambda skill; not 3: those generic terms are framed within LMI-specific contexts.

4 / 5

Total

18

/

20

Passed

Validation

93%

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

Validation — 15 / 16 Passed

Validation for skill structure

CriteriaDescriptionResult

frontmatter_unknown_keys

Unknown frontmatter key(s) found; consider removing or moving to metadata

Warning

Total

15

/

16

Passed

Repository

aws/agent-toolkit-for-aws

Path

skills/specialized-skills/serverless-skills/aws-lambda-managed-instances/SKILL.md

Reviewed

Table of Contents

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