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

Annotations cover the safety profile (readOnlyHint=false, openWorldHint=true, idempotentHint=false), and the description adds real context beyond them: the password is never returned (only a flag that it is set), the test email targets the key owner's address, and the log includes the mail server's refusal text. This meaningfully enriches the agent's expectations.

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?

A single dense paragraph that front-loads the core purpose before the capability list and the setup constraint. Slightly packed, but each clause conveys distinct behavior; no filler.

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 multi-action tool with no output schema, the description adequately covers what each action does and the nature of the returned data (settings, log with refusal text, test result). Minor gaps remain around log structure and limits, but the essentials for correct invocation are present.

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 (action enum, limit, offset, workspace_id) are already fully documented in the schema. The description reinforces the action meanings but adds no syntax or format detail beyond the schema, 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 description states a specific resource (the workspace's own SMTP mail service) and enumerates concrete capabilities: showing settings, toggling an existing connection, sending a test email, and returning the delivery log. It is clear what the tool does, though it never distinguishes itself from nearby siblings like get_mailing_state or manage_workspace_domain.

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 implied through the action-level breakdown (show/logs/enable/disable/test), and there is one useful exclusion — credentials must be created by a human in the dashboard and third-party credentials are rejected. However, no explicit when-to-use-vs-alternative routing against sibling tools is provided.

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