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

Annotations only supply the safety flags (readOnlyHint=false, idempotentHint=false, destructiveHint=true); the description goes further by disclosing the authorization model and confidentiality guarantees (service credential stays server-side, mailbox passwords and message content never returned). It does not state that existing destinations are replaced or that the change is irreversible, which is the main remaining gap given destructiveHint=true.

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 short sentences, front-loaded with the core action, with no wasted wording. The trailing credential/password sentences read as a reusable boilerplate block but still add relevant confidentiality context.

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 destructive, 4-required-parameter mutation with no output schema, the description covers permissions and data handling but omits what happens to the prior destinations, whether the operation is reversible, and how the idempotency_key affects retries. Adequate but with clear gaps.

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 all four parameters are already documented in the schema, and the description adds no format or semantic detail about destinations, resource_id, or idempotency_key. Baseline 3 is appropriate when the schema carries the full parameter burden.

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 states a specific verb and resource: 'Change the alias destinations within this organization.' An agent can distinguish this mutation from siblings like commsharbor_email_alias_create or commsharbor_email_alias_suspend. It stops short of naming any sibling explicitly, so it is clear but not fully differentiated.

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?

There is no guidance on when to use this tool versus commsharbor_email_alias_create or the mailbox update tools, nor any stated prerequisites beyond authorization roles. The role sentence ('No guest access. Members can read. Owners, admins and organization keys can manage email.') is access control, not usage routing.

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