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

Annotations already declare readOnlyHint=true and idempotentHint=true. The description adds valuable context about data sources ('live RegyREST domain data plus read-only ESB task fallback') and hints at a fallback mechanism, which goes beyond the annotations. No contradictions. The description contributes meaningful behavioral insight.

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?

The description is a single, well-structured sentence that immediately states the purpose and data sources. It is front-loaded with the action and resource, with no wasted words. Ideal conciseness.

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 read-only list tool with an existing output schema and high annotation coverage, the description sufficiently adds context about the data sources. It does not mention pagination or limits, which may be relevant for large accounts. However, given the output schema handles return structure, the description is largely complete. Minor gap in missing pagination detail.

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% with both parameters already described in the input schema. The tool description does not add any further meaning or context about the parameters (e.g., how partner_id affects the query or what pending includes). Per the rubric, baseline 3 is appropriate when schema covers the details.

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?

The description clearly states the tool lists domains for the authenticated Encirca account, specifying the data sources (live RegyREST data plus ESB fallback). This is distinct from sibling tools like list_expiring_domains or get_domain_details, making it easy for an agent to differentiate.

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 description provides no explicit guidance on when to use this tool versus alternatives like list_expiring_domains or suggest_available_domains. Usage is implied by the name and description, but no conditions, prerequisites, or exclusions are stated.

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