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

readOnlyHint=true already tells the agent this is a safe read, so the bar is lower. The description adds genuinely useful context: results are region-scoped and it names the returned fields. It says nothing about pagination, result limits, or auth requirements, so it is adequate rather than rich.

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 front-loaded sentence covering action, scope, and return payload, followed by a compact API-endpoint reference. Nothing is wasted and nothing important is buried.

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-optional-param read tool with annotations covering safety, the description is nearly complete — the field enumeration usefully compensates for the absent output schema. The remaining gap is pagination/result-limit behavior, which is not mentioned anywhere.

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?

Only one optional parameter with 100% schema coverage, so the schema already carries the semantics (pattern, default CIVO_REGION, cross-reference to civo_list_regions). 'In a region' restates the scoping but adds no syntax or behavior beyond the schema; baseline 3 applies.

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?

Specific verb ('List') plus resource ('private networks') plus scope ('in a region'), and it even enumerates the returned fields. The 'private networks' resource is clearly distinct from the other list_* siblings (instances, volumes, firewalls, clusters), so an agent can route to it without opening the schema.

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?

Usage is only implied by the read-only listing nature of the tool; there is no statement of when to choose this over alternatives or any prerequisite. It does implicitly point at civo_list_regions via the schema's region description, but the description itself offers no when/when-not guidance.

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