Retrieve a single OPNsense firewall filter rule by UUID with all fields, enabling inspection and verification of a specific rule's configuration before changes.
One filter rule by UUID, with all fields.
Args: uuid: rule UUID as shown by firewall_rules.
| Name | Required | Description | Default |
|---|---|---|---|
| uuid | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds that the full record is returned ("with all fields"), but says nothing about behavior when the UUID does not exist.
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?
Two short lines, with the outcome (one rule, all fields) front-loaded before the argument note. Nothing is padded or redundant.
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 one-parameter read tool with annotations covering the safety profile and no output schema, this is nearly complete; "with all fields" sets return expectations. The only gap is unspecified behavior for a missing or invalid UUID.
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 coverage is 0%, so the description must carry the parameter meaning, and it does: the single argument is a rule UUID and is sourced from the firewall_rules output. That is exactly the non-obvious information an agent needs to populate it.
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?
"One filter rule by UUID, with all fields" names a specific verb (retrieve) and resource (filter rule), scoped to a single record, which implicitly contrasts with the sibling firewall_rules list tool. The distinction is present but not stated as explicitly as it could be.
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?
The line "uuid: rule UUID as shown by firewall_rules" tells the agent to obtain the identifier from the list sibling, implying the list-then-fetch workflow. It stops short of stating when to use this versus firewall_rules or what to do when the UUID is unknown.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.