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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds two pieces of value beyond that: the required permission scope ('vms.read') and a clear statement of what the response contains (firewalls, inbound rules, protected machines, quota). It does not discuss volume or truncation behavior, keeping it just short of a 5.

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?

A single sentence with no filler, front-loading the resource and then the returned payload, with the permission scope appended last. Every clause adds information.

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 parameterless read tool with no output schema, the description supplies what an agent needs: what it returns, at what scope, and what permission it requires. Nothing material is left ambiguous.

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, which sets the baseline at 4. There are no arguments whose meaning needs explaining, and the description correctly says nothing about parameters beyond the account-level scope.

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?

Names a specific verb and resource (list the account's firewalls) and goes further by enumerating the contents returned: inbound rules, protected machines, and quota. It does not explicitly contrast with the singular sibling get_firewall, but the 'list' framing and account-wide scope make the distinction reasonably clear.

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 account's firewalls' – an agent can infer this is the bulk-listing call rather than a single-resource fetch. However, there is no explicit when-to-use guidance, no mention of when to prefer get_firewall for a specific firewall, and no prerequisites or exclusions stated.

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