Get message

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

Annotations provide readOnlyHint=true, and the description adds behavioral detail about what is returned (full message with specific components). This goes beyond the annotation by disclosing the output scope, which is helpful for the agent. No contradictions, and the read-only nature is consistent.

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, well-structured sentence that front-loads the core action ('Fetch one message in full') and lists return fields concisely. No wasted words, and every element adds value.

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 single-message fetch with existing annotations and a schema, the description is complete. It specifies what is returned, and the absence of an output schema is mitigated by the explicit list of returned fields. No additional context is needed for correct invocation.

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 covers 67% of parameters with descriptions for guild and channel. The description does not add any parameter-level semantics beyond what the schema provides; message_id is self-explanatory. Since coverage is not high (>80%), the description could have compensated, but it doesn't.

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 resource ('one message') and enumerates the included fields (author, content, timestamps, attachments, embeds, reactions, reply reference). This clearly distinguishes it from sibling tools like read_messages (list) and search_messages (search) by focusing on a single message retrieval.

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 context is clear: use this to fetch a single message in full, as implied by 'one message' and the required message_id parameter. It does not explicitly name alternatives or state when not to use, but the sibling list and parameter requirements make the usage apparent.

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