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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds real value beyond that: permission tiers per role and the security guarantees that the private service credential stays server-side and that mailbox passwords and message content are never returned.

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?

Four short sentences, purpose front-loaded, then access rules, then data-exposure guarantees. Nothing is redundant, though the role list is slightly compressed into one dense sentence.

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 return burden and names what comes back (setup, DNS records, readiness) while covering auth and data-exclusion rules. It stops short of describing structure or freshness of the 'observed readiness' data.

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 description coverage is 100% and both parameters (organization_id, resource_id) are documented in the schema, so the baseline of 3 applies. The description adds no syntax, format, or lookup guidance for either identifier.

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?

Specific verb ('Read') plus a concrete resource bundle ('domain setup, DNS records and observed readiness'), which clearly separates it from mutation siblings like commsharbor_email_domain_create, commsharbor_email_domain_setup and commsharbor_email_domain_verify. An agent can tell this is the read/inspect counterpart 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 description gives access context ('No guest access. Members can read. Owners, admins and organization keys can manage email.'), which effectively tells the caller whether they can invoke it. However it never states when to prefer this over domain_verify, domain_assistance, or workspace_snapshot, so the sibling selection is left to inference.

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