get_message

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

With no annotations, the description carries the behavioral burden. It meaningfully discloses the three output modes, notes that metadata is 'cheap,' and indicates what plain and full add. This gives useful behavioral context beyond just 'get a message,' even though it does not mention auth or error behavior.

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 tight sentences. The core purpose is front-loaded, and the format details are packed efficiently without 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?

The tool is simple, has an output schema, and the description covers the only non-obvious parameter behavior. It does not mention prerequisites like where account or message_id come from, but those are inferable from sibling tools, and the output schema handles return shape.

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 add meaning. It does exactly that for the format parameter by explaining the three allowed values and their payload differences. Account and message_id are left unexplained, but their names are self-evident and the schema marks them required.

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 'Get one message,' a specific verb and resource, and the format breakdown clarifies the scope. This distinguishes it clearly from sibling tools like messages_list or get_thread that operate on collections or threads.

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 implies this is for retrieving a single message by ID and offers format choices, but it never explicitly says when to prefer this over messages_list, search, or get_thread. There are no exclusions or named alternatives.

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