send

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

With no annotations provided, the description carries the full behavioral burden. It discloses that sending is disabled by default, requires an environment variable, follows chat matching rules like read_thread, and mandates explicit user confirmation. This gives an agent meaningful safety and prerequisite context beyond the basic action.

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 compact and efficient. The core purpose is front-loaded, followed by critical activation and safety instructions. No wasted words or redundant restatement of the schema.

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 simple two-parameter tool with an output schema, this description covers the essential operational context: activation, chat resolution, and the mandatory consent gate. Nothing critical is missing for an agent to call it safely and correctly.

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 0%, so the description must compensate for both parameters. It adds useful semantics for `chat` by referencing read_thread matching rules, but it does not explicitly define `text` beyond the obvious 'message text' implied by the tool's purpose and the consent warning.

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 opens with a specific verb and resource: 'Send a message through Messages.app.' This clearly distinguishes sending from the sibling tools (list_chats, read_thread, search, whats_new) without ambiguity.

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?

It provides explicit usage conditions: the tool is disabled by default, must be enabled via IMESSAGE_SEND=1, and must only be called after showing the exact text and getting user consent. It does not explicitly contrast with sibling tools, but the purpose is so distinct that exclusion feels implicit.

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