get_message

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

There are no annotations, so the description must carry behavioral context on its own. It clearly discloses that the tool retrieves the full message, returns headers, and includes a decoded text/plain body. This goes beyond a simple 'get message' phrase, though it does not cover error behavior or handling of non-text body parts.

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 communicates the action, target, and response content without any filler. Every word contributes to understanding.

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 get-by-id tool with one parameter and no output schema, the description covers the essential behavior: fetching the full message and what it includes. It is adequately complete, though it omits details like error semantics and non-plain-text body handling.

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?

The schema has one parameter, message_id, with 0% description coverage. The tool description only restates that the message is fetched 'by id,' adding little meaning beyond the property name. It does not clarify the ID format, provenance, or any constraints, so it does not compensate meaningfully for the missing schema description.

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 uses a specific verb ('Fetch') and a clear resource ('full message by id'), and it further specifies what is included: 'headers plus decoded text/plain body.' This differentiates it from sibling search_messages, which would be used for finding messages rather than retrieving one by id.

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 'by id' implies the tool is for direct retrieval when a message_id is already known, as opposed to search_messages for discovery. However, the description does not explicitly state when to use this tool vs alternatives or mention exclusions, so the guidance is only implied.

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