list_accounts

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

No annotations are provided, so the description carries the burden, but for a zero-parameter enumeration tool the surface is small. It does usefully declare 'Read-only', which reassures the agent this is a safe non-mutating call, but adds nothing about return volume, ordering, or failure modes.

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 short sentences, front-loaded with the verb and resource, and the read-only attribute appended economically. No filler or 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?

For a trivial enum-style listing with no parameters and no output schema, the description effectively conveys what is returned (accounts plus configured sender addresses). Only the absence of any output schema leaves minor ambiguity about the exact field shape, which is not required for correct invocation.

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?

The tool takes zero parameters, so there is no parameter semantics to explain; the baseline for a 0-param tool applies. Nothing in the schema needs compensating for.

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?

States a specific verb ('List') and a specific resource ('Apple Mail accounts and their configured sender addresses'), which is distinct from the sibling list_mailboxes and list_messages. It does not explicitly name which sibling to prefer, but the resource itself is unambiguous.

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?

No guidance on when this tool is appropriate versus alternatives such as list_mailboxes; the agent must infer that accounts are the prerequisite to mailbox/message operations. No prerequisites or exclusions are stated.

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