Agent Documents Filenames
Agent configuration must document which instruction filenames it checks and in what priority order.
MediumcorestructureAgent Memory Directory
Agent memory must be stored in a dedicated directory, separate from instruction content.
MediumcorestructureBuild And Test Commands
The instruction file must include build and test commands that the agent can run. Without these, the agent can't verify its own changes work correctly.
MediumcorecoherenceChild Nested Instructions
Child instruction files must extend their parent's scope without contradicting it. Contradictions between levels create confusion.
MediumcorestructureCode Block Examples Present
The instruction file must contain fenced code blocks with concrete examples. Code blocks are the clearest way to show the agent exact syntax and patterns.
MediumcorecoherenceCommand Workflow Documented
The instruction file must document command workflows — ordered sequences of steps for common operations like building, testing, and deploying.
MediumcorecoherenceConditional Scope
Conditional instructions ("When X, do Y") are not uniformly weaker than unconditional ones. The "When X" scope text activates the model's knowledge about what's conventional in that domain. If the convention aligns with the instruction, the scope helps. If it conflicts, the scope actively hurts.
MediumcorecoherenceNo Credentials
Instruction files must never contain credentials, API keys, or private keys. Secrets in instruction files get committed to version control.
MediumcoregovernanceDefault Behavior Competition
The model always has a default behavior for any task — what it does without instructions. When instructions conflict or are too weak, the model reverts to this default completely. The default is an ever-present competitor.
MediumcorecoherenceDescription Coherence
Files that the agent loads on demand — skills, subagents, slash commands — are dispatched by their frontmatter description: field. The agent reads the description first, decides whether the file applies, and only then loads the body. When the description names a narrower concept than the body covers, or when the description and the body are about different topics altogether, the agent never invokes the file for the cases it actually contains.
MediumcorecoherenceDirection Imbalance
Directives and constraints within the same topic must have balanced strength. When prohibitions are written more strongly than enabling instructions, the agent may suppress the intended behavior entirely rather than conditionally gating it.
MediumcoredirectionForbidden Commands Defined
The main instruction file must contain at least one constraint atom that prohibits specific commands or actions. Listing forbidden operations prevents the agent from executing destructive commands like git push --force, rm -rf, or database mutations without explicit user approval.
MediumcoregovernanceHeading As Instruction
Headings should organize content into sections, not carry instructions. The model processes heading content the same as body content, but instructions in headings are structurally fragile — they get lost when files are reorganized, and they can't carry the detail an instruction needs.
MediumcorestructureHook Event Handlers
Config files that define hooks or event handlers must include a heading matching Hook, Event, Trigger, or Pre-commit. Without a labeled section, trigger conditions are buried in unstructured content where they are easy to miss.
MediumcorestructureHook Uses Project Dir Variable
Hook commands must not contain hardcoded absolute paths like /home/user/project/. The check flags "command" values that start with common Unix/macOS base directories. Agent-specific rules supersede with checks for the correct project dir variable per agent.
MediumcoregovernanceImport Depth Within Limit
Import chains in root instruction files should be bounded. Deep import hierarchies increase context loading time and create fragile dependency chains; a change to a deeply nested file can silently break import resolution of files several levels up. The CORE check enforces a permissive absolute ceiling (10 hops) — agents whose @<path> syntax has a documented behavior should declare a per-agent supersede stub with the actual threshold. Of the agents currently in the registry: Claude defines a 5-hop hard limit (see CLAUDE:S:0010); Cursor's @filename is single-level only (see CURSOR:S:0002); Gemini supports chained @file.md imports without a documented max and inherits the CORE ceiling; Codex and Copilot declare CORE:S:0033 in their config.yml excludes: because their instruction files do not honor any @<path> inclusion syntax.
MediumcorestructureImport References Resolve
Every @path import reference in an instruction file must resolve to an existing file. Broken import references create phantom context — the agent sees the import directive but the referenced content never loads, causing silent gaps in its instruction set.
MediumcorestructureImport Targets Resolve
Import references in instruction files must resolve to existing files. Broken imports create gaps in the agent's context — the agent silently skips missing files without warning.
MediumcorestructureInstruction Rationale Present
The default pattern for instructions is a directive or imperative followed by brief context within a focused length. When you need to suppress a behavior, use the golden pattern: directive first, brief positive context, then constraint last. You don't need a constraint for every directive — add constraints only when your goal is to explicitly prevent something.
MediumcorecoherenceItalic Constraints
Constraint instructions (-1 charge) should be wrapped entirely in italic markdown. Full-sentence italic signals the charge type visually, separating the constraint from the directive (+1) and reasoning (0) that precede it.
MediumcoreefficiencyLayered Content Structure
Instruction content must be organized with at least two top-level headings for major topics. This lets the agent quickly find relevant sections instead of scanning a flat wall of text.
MediumcorestructureMcp Config Declares Servers
Config files must contain a heading referencing MCP or mcpServers. Without declared server entries, the agent has no record of which MCP tools are available or how they are scoped.
MediumcoregovernanceMcp Configuration Documented
The main instruction file must contain a heading referencing MCP, Server, or Tools. If the project uses MCP tools, documenting them in the main file ensures the agent discovers available servers at session start.
MediumcorecoherencePath Scope Declared
Path-scoped instruction files must declare which paths they apply to via a frontmatter key. Without a scope declaration, the file loads for all contexts instead of being scoped to specific files.
MediumcorestructurePermission Config Denies Sensitive
Configuration files must contain at least one constraint instruction that restricts access to sensitive files. Without an explicit denial, the agent may read or write secrets, credentials, and private keys.
MediumcoregovernancePermissions Ordered
Permission declarations in agent configuration must follow a deterministic order — deny rules before allow rules, specific patterns before broad wildcards. First-match-wins semantics in permission evaluation mean ordering determines which rule fires. A broad allow: Bash() before a specific deny: Bash(rm -rf ) silently permits the dangerous command.
MediumcoregovernanceProject Config Self Contained
Project configuration must be self-contained — no dependencies on user-specific setup or external state not documented in the project.
MediumcoregovernanceRelated Instructions Grouped
Related instructions must be grouped together, not scattered across the file. Co-location reduces the agent's search effort.
MediumcoreefficiencyRelevance Decay
Instructions are only effective for tasks they're semantically related to. A testing instruction has no effect on documentation tasks — the instruction must be relevant to the work at hand.
MediumcorecoherenceRules Directory Structure
When scoped rule files exist, they must reside in the expected directory for the agent (e.g., .claude/rules/). This ensures the agent discovers and loads rules correctly at session start.
Mediumcorestructure