list_rulesLists all rule IDs defined in a YAML rules file so you can reference valid rules when evaluating yes/no or multiple-choice decisions.
Show the rules defined in the rules file, so you know which rule_ids exist.
| Name | Required | Description | Default |
|---|---|---|---|
| rules_file | No | Path to a rules YAML file. Default: JEV_RULES_FILE env var, then .jev/rules.yaml in the working directory. |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations exist, so the description carries the burden. 'Show' implies a non-destructive read, which is the key behavioral trait for this tool, and it hints at the returned content (rule_ids). But it says nothing about behavior when the file is missing, empty, or when the env-var default fails to resolve.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
One sentence, zero waste, with the action front-loaded and the motivation trailing. Nothing to trim and nothing missing for the size.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a zero-required-parameter read-only listing tool with no output schema, the description supplies the action, the target file, and the reason to call it. Return shape is only loosely hinted ('rule_ids'), which is a minor gap given no output schema exists.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100% for the single rules_file parameter, including the env-var and working-directory default chain, so the baseline is 3. The description adds no format or resolution details beyond what the schema already documents.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
States a specific verb and resource ('Show the rules defined in the rules file') and adds the agent-facing purpose of discovering valid rule_ids. It does not explicitly differentiate itself from the sibling evaluate_rules, though the discover-vs-evaluate distinction is implied.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
'so you know which rule_ids exist' implies the usage context: consult this before invoking evaluate_rules. However, no alternative is named and no when-not-to-use condition is given, so the guidance is implied rather than explicit.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.