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

readOnlyHint=true already declares the safety profile, so the bar is lower. The description adds genuinely useful context beyond the annotation: the scope of visibility (account-visible networks), the per-entry contents (subnets, DHCP, routes, attached servers, peerings), and the underlying GET /1.3/network/ endpoint.

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 tight sentences with the resource and scope front-loaded, followed by the endpoint reference. Only the API-path tail is arguably expendable, but it is short and useful for disambiguation.

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?

With no output schema, the description compensates by naming the fields returned per network, which is what an agent needs to decide relevance. It omits pagination/ordering behavior and says nothing about the label parameter, but coverage is largely adequate for a read-only list tool.

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%, so both parameters are already documented in the schema. The description only echoes the zone filter ('Optionally only one zone') and says nothing about the label filter, so it adds little beyond the schema — the 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?

States a specific verb and resource (list networks) and enumerates the network kinds returned — public, utility and private SDN — plus the fields each entry carries. This clearly separates it from siblings such as upcloud_list_zones or upcloud_list_servers.

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 phrase 'Optionally only one zone' implies the filtering context, but there is no explicit when-to-use guidance, no prerequisites, and no named alternative (e.g. a get-network-by-id tool). Usage is only implied.

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