apple_mail_list

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

Annotations already declare read-only, idempotent, and non-destructive. The description adds valuable behavioral context beyond these: it lists exact metadata fields returned, clarifies that message bodies are not accessed, and scopes to 'local Apple Mail metadata'. This transparency helps an agent understand side effects (none) and output granularity.

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 description is two sentences, with the primary action and scope front-loaded ('Read-only: list local Apple Mail metadata'). The second sentence adds return fields and an explicit exclusion (no bodies). Every word earns its place with 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 no output schema, the description compensates by listing the returned fields and clarifying body exclusion. It also covers the local scope. Minor gaps exist (e.g., no mention of ordering, pagination, or default mailbox) but the schema provides defaults for account and mailbox, and the simplicity of the tool reduces the need for more detail.

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%, as each parameter (limit, account, mailbox) has a clear description. The tool description adds no additional parameter-specific detail beyond the schema, so a baseline score of 3 is appropriate; the schema carries the semantic load.

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 uses a specific verb ('list'), names the resource ('local Apple Mail metadata'), and enumerates return fields (message ID, sender, subject, received time, read/flag status). It clearly distinguishes from siblings like apple_mail_get (which reads bodies) and apple_mail_send/delete/move (which mutate mail).

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?

The description establishes clear context: it is a read-only listing operation and explicitly states it does not read message bodies, which implies use apple_mail_get when bodies are needed. It does not explicitly name alternatives or provide when-not-to-use instructions, but the context is sufficiently clear for safe selection.

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