Messages Reply In Conversation

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

Annotations provide some safety context (openWorldHint true, idempotentHint false, destructiveHint false), but the description adds no behavioral information beyond that. It does not disclose side effects, permissions, conversation-scoping behavior, or what happens on reply.

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 short but only because it is nearly empty of content, not because it is economically structured. It does not front-load any useful behavioral or semantic information, so the single sentence fails to earn its place.

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?

Despite having an output schema and siblings that hint at messaging actions, the description is inadequate for an agent to know how to invoke this tool correctly. Critical context is missing: what a conversation is, what format chat_id uses, whether this is a reply versus a new message, and when to choose it over messages_send_message.

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%, and the description adds no meaning to chat_id or text. The schema only gives types and titles, so an agent has no guidance on what chat_id should contain, what text should be, or how they relate to replying in a conversation.

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 only states that the tool is a 'Delegated Apple domain tool' exposed through Apple-Tools-MCP, which restates the tool's name and provenance without describing what the tool does. No verb, resource, or action is specified, so an agent cannot determine that this replies to an existing conversation.

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 provides no guidance on when to use this tool versus alternatives like messages_send_message, mail_reply_message, or messages_get_conversation. There is no context, no exclusions, and no indicated preference among sibling tools.

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