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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=false), and the description goes further: it confirms data preservation, states that guest access is excluded and members retain read access, and discloses that credentials stay server-side and passwords/message content are never returned. This is meaningful context beyond the annotations. It does not address idempotency behavior despite a required idempotency_key, which is a notable omission.

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 purpose is front-loaded in the first sentence, which is good. However, the trailing sentences about the private service credential and never-returned passwords read as generic service boilerplate that may not earn its place in a single-mutation tool description, making it slightly padded rather than tight.

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 three-required-parameter mutation with no output schema, the description covers behavior and permission context adequately. It leaves gaps on when to prefer this over resume/delete, and it never explains the required idempotency_key even though annotations declare idempotentHint=false, which is a genuine ambiguity an agent would want resolved.

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%, so resource_id, idempotency_key, and organization_id are already documented by the schema. The description adds no syntax, format, or constraint detail beyond that, so the baseline 3 applies.

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 opening sentence names a specific verb and resource ('Suspend access' on a mailbox) plus the key side effect ('while preserving mailbox data'), which immediately distinguishes it from a delete. It does not explicitly name the counterpart sibling (commsharbor_email_mailbox_resume) or clarify suspend vs. alias_suspend, so it falls short of full sibling differentiation.

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 only implied: an agent can infer this is the tool to disable a mailbox reversibly, but there is no explicit 'use this when / use resume instead' routing and no stated prerequisites for when suspension is appropriate. The permission sentence ('Owners, admins and organization keys can manage email') is closer to auth policy than to when-to-use guidance.

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