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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds meaningful behavioral detail: one entry per requested domain, preservation of request order, and a specific error-shape for unresolvable domains. This goes well beyond the structured annotations.

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?

Well-structured with clear USE FOR / DO NOT USE FOR / RETURNS sections. Every sentence contributes distinct information, and the core purpose is front-loaded. No filler or redundancy.

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 single-parameter read-only tool with no output schema, the description fully covers invocation, return format, and error handling. Nothing critical is missing for an agent to call this correctly and parse the result.

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 coverage is 100% and the schema already documents domains as strings with an example. The description adds value by clarifying the cardinality mapping – one output entry per requested domain – and that order is preserved, which helps an agent interpret results correctly.

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?

'Get comprehensive account details for specific domain(s)' clearly states a specific verb, resource, and scope. The description explicitly distinguishes itself from get_insights_report, which is the closest alternative, so an agent can tell them apart immediately.

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?

Explicit 'USE FOR' and 'DO NOT USE FOR' directives with a named alternative (get_insights_report) leave no ambiguity about when to invoke this tool versus its sibling. The guidance is direct and actionable.

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