apple_mail_send

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

Annotations already declare readOnlyHint=false, idempotentHint=false and openWorldHint=true, so the mutation/irreversibility profile is largely covered. The description adds the useful nuance that dispatch is immediate (i.e. not queued, not undoable), but says nothing about account selection behavior, send failures, or what happens if the account is unavailable. With annotations carrying the safety profile, this is adequate but not rich.

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 action and followed by the most decision-relevant consequence (immediate send). No filler, though the second sentence partially restates the first.

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?

A six-parameter mutation tool with 33% schema coverage, no output schema, and no parameter elaboration in the description leaves the agent under-informed about subject/body/cc/bcc and about the account parameter versus the 'selected local account' phrasing. For this complexity level the description should do considerably more.

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 only 33% – only 'to' and 'account' are documented, and the description adds no field-level meaning for subject, body, cc, or bcc. With low coverage the description is expected to compensate, and it does not; it also introduces a mild ambiguity by saying 'the selected local account' while a separate account parameter exists.

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 ('Send an Apple Mail message') and identifies the originating account, which is enough to distinguish it from read-only siblings like apple_mail_list or apple_mail_get. It does not explicitly name the nearest alternative (apple_mail_create_draft), so it falls short of full sibling differentiation.

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 phrase 'immediately sends email' implies this is the direct-dispatch path rather than the draft path, giving implied usage guidance. However, it never states when to prefer apple_mail_create_draft over sending, nor any prerequisite conditions, so the guidance is inferred rather than stated.

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