docs: Refresh and simplify SDK agent guidance

[marandaneto]

💡 Motivation and Context

The review rule can incorrectly flag an external API change that already has an API-defining published SDK spec. The contributor-guide inventory also repeats guidance available through its link.

Clarify that an API-defining published SDK spec satisfies the external contributor review agreement. Remove the contributor-guide section inventory while retaining maintainer verification, issue consent, and changed-behavior-only spec checks.

💚 How did you test it?

Checked local Markdown links, exact Git path casing, anchors, code fences, whitespace, changed-file scope, and preservation of the API approval and scoped spec-review rules. SDK runtime builds and tests were not run for this documentation-only change. Autoreview was skipped because every changed file is documentation.

📝 Checklist

• I reviewed the submitted changes.
• I added tests to verify the changes.
• I updated the docs if needed.
• No breaking change or entry added to the changelog.

No SDK code changes. Runtime tests and release changesets are not needed for this documentation-only PR.

If releasing new changes

• Ran pnpm changeset to generate a changeset file

Not applicable. This PR does not release SDK changes.

🤖 Agent context

Autonomy: Human-driven (agent-assisted)

Tools: Pi, Git, and GitHub CLI. The SDK-wide documentation audit used Pi subagents for implementation and independent reviews. The human driver approved the audit and simplification plan. Useful details were moved to focused local guides rather than deleted. Human review is still required. No public session link is available.

[greptile-apps]

[Low risk] Updates guidance text for SDK contributors and agents.

The documentation change appears safe to merge.

_{Reviews (1) · Last reviewed commit: "docs: Refresh and simplify SDK agent gui..."}

[github-actions]

posthog-dotnet Compliance Report

Date: 2026-10-05T08:50:21.190074+00:00
Duration: 125036ms

✅ All Tests Passed!

47/47 tests passed

---

Capture Tests

✅ 30/30 tests passed

View Details

Test	Status	Duration
Format Validation.Event Has Required Fields	✅	265ms
Format Validation.Event Has Uuid	✅	129ms
Format Validation.Event Has Lib Properties	✅	112ms
Format Validation.Distinct Id Is String	✅	115ms
Format Validation.Token Is Present	✅	111ms
Format Validation.Custom Properties Preserved	✅	119ms
Format Validation.Event Has Timestamp	✅	111ms
Format Validation.Non Utc Event Timestamp Is Converted To Utc	✅	120ms
Retry Behavior.Retries On 503	✅	8124ms
Retry Behavior.Does Not Retry On 400	✅	2119ms
Retry Behavior.Does Not Retry On 401	✅	2112ms
Retry Behavior.Respects Retry After Header	✅	8121ms
Retry Behavior.Implements Backoff	✅	22134ms
Retry Behavior.Retries On 500	✅	6118ms
Retry Behavior.Retries On 502	✅	6119ms
Retry Behavior.Retries On 504	✅	6116ms
Retry Behavior.Max Retries Respected	✅	22136ms
Deduplication.Generates Unique Uuids	✅	116ms
Deduplication.Preserves Uuid On Retry	✅	6117ms
Deduplication.Preserves Uuid And Timestamp On Retry	✅	13129ms
Deduplication.Preserves Uuid And Timestamp On Batch Retry	✅	6121ms
Deduplication.No Duplicate Events In Batch	✅	118ms
Deduplication.Different Events Have Different Uuids	✅	110ms
Compression.Sends Gzip When Enabled	✅	111ms
Batch Format.Uses Proper Batch Structure	✅	110ms
Batch Format.Flush With No Events Sends Nothing	✅	105ms
Batch Format.Multiple Events Batched Together	✅	113ms
Error Handling.Does Not Retry On 403	✅	2111ms
Error Handling.Does Not Retry On 413	✅	2113ms
Error Handling.Retries On 408	✅	6114ms

Feature_Flags Tests

✅ 17/17 tests passed

View Details

Test	Status	Duration
Request Payload.Request With Person Properties Device Id	✅	148ms
Request Payload.Flags Request Uses V2 Query Param	✅	109ms
Request Payload.Flags Request Hits Flags Path Not Decide	✅	109ms
Request Payload.Flags Request Omits Authorization Header	✅	111ms
Request Payload.Token In Flags Body Matches Init	✅	110ms
Request Payload.Groups Round Trip	✅	114ms
Request Payload.Groups Default To Empty Object	✅	108ms
Request Payload.Disable Geoip False Propagates As Geoip Disable False	✅	109ms
Request Payload.Disable Geoip Omitted Defaults To False	✅	109ms
Request Payload.Flag Keys To Evaluate Contains Only Requested Key	✅	110ms
Request Lifecycle.No Flags Request On Init Alone	✅	5ms
Request Lifecycle.No Flags Request On Normal Capture	✅	110ms
Request Lifecycle.Two Flag Calls Produce Two Remote Requests	✅	216ms
Request Lifecycle.Mock Response Value Is Returned To Caller	✅	113ms
Retry Behavior.Retries Flags On 502	✅	1114ms
Retry Behavior.Retries Flags On 504	✅	1113ms
Side Effect Events.Get Feature Flag Captures Feature Flag Called Event	✅	212ms