Get Relay Message

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

The annotation block already declares readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is well covered. The description does not add meaningful behavioral context beyond that, such as how missing/invalid IDs are handled or what fields the response includes, but the bar is lower given the rich annotations.

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 with no filler or repetition. Every word carries meaning and the core action, object, and lookup key are all present.

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?

Given the simple one-parameter read-only operation and strong annotations, the description is nearly complete. It does not explicitly describe the return value or error behavior, but 'Retrieve' clearly implies the message is returned, and the annotations cover safety semantics.

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 input schema has 0% description coverage, so the description must compensate. It does link message_id to the retrieval action ('by ID'), but it does not explain the semantics of the ID beyond what the property name and UUID format already imply. For a single obvious parameter, this is adequate though minimal.

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 ('Retrieve') and resource ('one Relay Message') plus the mechanism ('by ID'). This clearly distinguishes it from sibling tools like relay_list_messages, which list messages, and relay_get_message_thread, which retrieves a different resource.

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 makes the usage context clear: use this when you need a single Relay Message identified by its ID. It does not explicitly mention alternatives or when-not-to-use conditions, but the 'one ... by ID' wording implies it is not for listing, sending, or thread retrieval.

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