chore: doc writing rules for the agents

Author: albinsuresh

AGENTS.md

@@ -288,6 +288,12 @@ Use the `.agent/skills/add-integration-test` skill while creating new tests.
 - **Safety**: `#![forbid(unsafe_code)]` in all crates
 - **Release profile**: `opt-level = "z"`, LTO enabled, symbol stripping (optimized for embedded)
 
+## Markdown style
+
+When writing or editing Markdown documents, use [semantic line breaks](https://sembr.org/):
+start a new line after each sentence, and optionally break long sentences
+at clause boundaries (after commas, semicolons, colons, or dashes).
+
 ## Troubleshooting
 
 ### Build Issues

openspec/config.yaml

@@ -1,20 +1,30 @@
 schema: spec-driven
 
-# Project context (optional)
-# This is shown to AI when creating artifacts.
-# Add your tech stack, conventions, style guides, domain knowledge, etc.
-# Example:
-#   context: |
-#     Tech stack: TypeScript, React, Node.js
-#     We use conventional commits
-#     Domain: e-commerce platform
+context: |
+  Writing style (all artifacts): plain, direct English.
+  Use semantic line breaks.
+  Clear, complete sentences. Prefer concise, but never at the cost of ambiguity.
+  Bullets for lists of items; short paragraphs for explanations and context.
+  No hedging or filler.
+  Avoid restating well known MQTT and thin-edge concepts.
+  State each decision and its reason. Skip elaboration unless a reader would
+  need to infer a non-obvious connection.
+  Never let terseness introduce ambiguity about scope — if a phrase could be
+  read two ways, spell out which reading is meant.
 
-# Per-artifact rules (optional)
-# Add custom rules for specific artifacts.
-# Example:
-#   rules:
-#     proposal:
-#       - Keep proposals under 500 words
-#       - Always include a "Non-goals" section
-#     tasks:
-#       - Break tasks into chunks of max 2 hours
+rules:
+  proposal:
+    - After "Why", add a "Proposed solution" section that introduces the feature from the
+      user's point of view with short usage examples —before any internal mechanism.
+    - In "What Changes", lead with what the feature introduces — 
+      what a user or consumer would interact with —
+      before stating its properties or constraints (opt-in, security model,
+      correctness guarantees).
+      Don't qualify something the reader hasn't met yet.
+  design:
+    - Do not restate the problem or motivation — that lives in the proposal. Link the
+      proposal instead of repeating its "Why".
+    - "Open with a brief Context: name the problem being solved (one sentence, link the
+      proposal for detail) and the constraints that shape the design decisions."
+    - Assume a reader who already knows the problem and the user-facing surface.
+      Spend the words on how it is built and why this design over the alternatives.