List SimpleLogin Mailboxes

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

Annotations already provide readOnlyHint. Description adds useful detail about the 'verified' field, indicating that false means mailbox can't receive mail. Lacks information on pagination or rate limits, but acceptable for a simple list tool.

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?

Two sentences, directly to the point. First sentence states purpose and resource; second adds critical usage guidance and a notable output property. No redundancy.

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 an output schema present, description need not detail return values. Covers purpose, usage, and a key output nuance. Could mention ordering or filtering, but not essential for a list of mailboxes.

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 a well-described optional parameter. Description does not add further semantics beyond what the schema provides, meeting the baseline.

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?

Clearly states verb 'List' and resource 'mailboxes (destination addresses)'. Differentiates from sibling tools like alias_list (aliases) and alias_create_mailbox (create). Provides usage context: 'Use the returned ids with alias_update / alias_create_custom'.

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?

Explicitly states how to use the ids for routing aliases. Implicitly distinguishes from other list tools (e.g., alias_list_domains) but does not state when not to use it.

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