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

readOnlyHint=true already establishes the safe-read profile, so the bar is lower, and the description usefully discloses that the scope is the entire account (unfiltered, no query options). It says nothing about pagination, result size, permissions, or ordering, which are the remaining behavioral traits an agent would want for a listing call.

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 front-loads the scope and then lists the returned fields; the trailing 'UpCloud: GET /1.3/ip_address' is a compact endpoint anchor. Nothing is padded or repeated, and the ordering puts the most decision-relevant information first.

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 carries the burden of explaining what comes back and does so field by field, which is genuinely helpful. The only gap is operational detail such as pagination or ordering for a list that could be large.

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?

The tool takes zero parameters, so per the rubric the baseline is 4. The field enumeration in the description describes return values rather than inputs and does not conflict with the empty schema.

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 the resource precisely ('Every IP address on the account') and enumerates exactly what the result contains, from address family to release policy. An agent can distinguish this from upcloud_list_networks, upcloud_list_servers and the other list_* siblings without opening a schema, since no sibling covers IP addresses.

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 implied by the resource and the all-encompassing scope ('Every IP address on the account'), which signals that no filtering is offered. There is no explicit when-to-use, when-not-to-use, or pointer to an alternative tool, so it stays at the minimum-viable level.

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