Get message status

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

With no annotations, the description carries the full burden. The phrase 'look up' indicates a read-only operation, and 'delivery status' implies it returns state information. It doesn't describe error conditions, rate limits, or side effects, but for a simple status lookup, this is adequate. It avoids contradictions and provides enough behavioral context.

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 a single, front-loaded sentence that states the purpose and scope efficiently. There is no waste or redundancy. It gets straight to the point and is easy to parse.

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 tool with one parameter and no output schema, the description provides enough context. It tells the agent what the tool does and the parameter's origin. It doesn't describe the return format, but for a status lookup, the agent can infer that it returns a status value. Given the low complexity, the description is sufficiently complete.

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 the parameter already has a meaningful description ('The message id returned by send_imessage'). The tool description does not add further parameter semantics beyond what the schema provides. Since the schema covers it well, baseline 3 is appropriate.

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 clearly states the tool's function: to look up the delivery status of a message by id. It names the specific resource (Blue Reacher message) and distinguishes it from siblings like send_imessage, list_conversations, and check_imessage_capability. The purpose is unambiguous and specific.

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 parameter description mentions the id is returned by send_imessage, which gives clear context that this tool is used after sending a message. It implies the workflow of sending first then checking status. While it doesn't explicitly say when not to use it, the intended usage is well implied. No alternatives are named, but the sibling list makes the distinction clear.

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