Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already flag destructiveHint=true, and the description goes further by explaining the blast radius ('changes what is reachable on every instance, cluster and load balancer') and the undo method. It does not cover auth requirements or rate limits, but the added context is substantial.

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?

Four short sentences, each earning its place: purpose and example first, then impact, undo, and API endpoint. No unnecessary repetition or filler.

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 nine-parameter mutation with no output schema, the description supplies the missing behavioral context—impact, reversibility, and API mapping—while annotations cover the destructive hint. It omits success/return behavior, but that is a minor gap given the absence of an output schema.

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 100%, so the schema already documents all nine parameters. The description adds a concrete example ('allow TCP 443 ingress from 0.0.0.0/0') and advises narrow CIDRs, which maps parameters to a real use case beyond the schema's field definitions.

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 ('Add') and resource ('one rule to a firewall') with a concrete example, making its function unmistakable. It does not name a sibling tool to contrast with, so it stops short of perfect sibling differentiation.

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?

Offers implied context (use when adding a rule) and a safety guideline to prefer narrow CIDRs, plus an undo path via dashboard/CLI. It never states when not to use this tool or names an alternative (e.g., civo_list_firewall_rules for inspection), leaving the agent to infer usage.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.