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exploring-apm-traces

Investigates distributed application performance using PostHog APM (OpenTelemetry span) data via MCP. Use when the user asks about service traces, slow HTTP/database spans, error spans, error-rate trends or spikes, latency distributions, trace IDs, or span attributes — not AI observability traces or product logs. Uses posthog:query-apm-spans, posthog:apm-trace-get, posthog:apm-spans-sparkline, posthog:apm-services-list, posthog:apm-attributes-list, and posthog:apm-attribute-values-list.

71

Quality

88%

Does it follow best practices?

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SecuritybySnyk

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The risk profile of this skill

SKILL.md
Quality
Evals
Security

Quality

Content

82%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-organized, highly actionable investigation skill with concrete tool calls, scripts, and pattern-based workflows. Minor conciseness and workflow-validation gaps, and the referenced bundle files could not be confirmed present.

Suggestions

State the '_posthogUrl must always be surfaced' rule once in a single authoritative place (e.g. the Tips or UI-links section) and reference it elsewhere instead of repeating it three times.

Add an explicit verification checkpoint to the trace-debug workflow (e.g. confirm is_root_span / parent_span_id resolution before interpreting the tree) so the sequence has a hard validation gate.

Ensure the referenced ./references/spans-and-fields.md and ./scripts/*.py files ship with the skill bundle so the signaled navigation targets actually resolve.

DimensionReasoningScore

Conciseness

Dense and mostly lean, but the instruction to always include '_posthogUrl' is repeated three times (lines 56, 155, 246) and a few gotchas restate earlier points; trimming those would reach 5.

4 / 5

Actionability

Copy-paste-ready JSON tool-call examples and exact bash invocations with env vars (SPAN=, SEARCH=, MAX_LEN=) cover the common investigation cases fully.

5 / 5

Workflow Clarity

Numbered workflows (debug from URL, each investigation pattern) are clearly sequenced with confirmation steps (re-run without filter, zoom on spike bucket), but these are analytical confirmations rather than hard pass/fail validation gates.

4 / 5

Progressive Disclosure

Good one-level-deep structure with clearly signaled references (tool table, script table, markdown links) and appropriate content splitting, but the referenced ./references/spans-and-fields.md and ./scripts/*.py files are not present in the bundle to verify.

4 / 5

Total

17

/

20

Passed

Description

95%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, third-person description that crisply states purpose, gives concrete triggers, and explicitly disambiguates from sibling skills. The only minor gap is that the capability side rests on one main verb rather than a list of distinct actions.

DimensionReasoningScore

Specificity

Names the domain ('PostHog APM (OpenTelemetry span) data via MCP') and the concrete action ('Investigates distributed application performance'), plus enumerates six specific tools; the 'what' is a single main verb so coverage is strong but not maximally comprehensive.

4 / 5

Completeness

Explicitly answers both what ('Investigates distributed application performance...') and when ('Use when the user asks about...') with concrete trigger phrases.

5 / 5

Trigger Term Quality

'service traces, slow HTTP/database spans, error spans, error-rate trends or spikes, latency distributions, trace IDs, or span attributes' comprehensively covers the natural phrases a user would say, including synonyms.

5 / 5

Distinctiveness Conflict Risk

Clear niche (PostHog APM/OTel traces) with an explicit exclusion ('not AI observability traces or product logs') that minimizes conflict with adjacent skills.

5 / 5

Total

19

/

20

Passed

Validation

87%

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

Validation — 14 / 16 Passed

Validation for skill structure

CriteriaDescriptionResult

relative_links

Relative link issues: 7 missing

Warning

referenced_paths_exist

Referenced path issues: 13 missing

Warning

Total

14

/

16

Passed

Repository
PostHog/posthog
Reviewed

Table of Contents

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