List Domains

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered; the description still adds value by disclosing the markdown return format, the truncation behavior on large results, and an explicit no-side-effects statement. It does not mention pagination or auth requirements, so it is not fully 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?

Five labeled, single-line sections that are front-loaded and waste no words; purpose precedes inputs and side effects in the order an agent needs them.

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 zero parameters, no output schema, and annotations already carrying the safety profile, the description supplies everything else needed: what it returns, how large results behave, and that there are no side effects.

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 and the description confirms 'Inputs: None,' consistent with the empty schema. Baseline for a 0-param tool is a 4 since there is nothing further to disambiguate.

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 (Enumerate) and resource (mail domains via the FortiMail Engine), and is clearly distinguishable from the sibling domains.get, domains.create, domains.update, and domains.delete. An agent can tell it is the unfiltered list operation 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?

The 'When to use' line gives concrete contexts (onboarding, audits, before editing a domain), which implicitly routes the agent away from domains.get when it needs the full set. It stops short of explicitly naming the alternative tools or when-not-to-use conditions, so it falls just short of a 5.

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