Retrieve full original message content

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

With readOnlyHint=true in the annotations, the non-mutating nature is already declared. The description adds that the tool returns original text and rich text and addresses truncation, but it does not elaborate on the response format, content structure, or error behavior, leaving the description to carry only partial behavioral detail.

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 immediately states the action and resource, then follows with a concise trigger condition. Every word contributes to the meaning, with no redundancy or filler.

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 tool's low complexity (two string parameters, read-only annotation, no output schema), the description sufficiently covers purpose, usage context, and return content. Combined with the fully documented schema and annotations, an agent has all needed information to invoke it correctly.

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 covers both parameters with clear descriptions for message_id and conversation_thread_id, achieving 100% coverage. The tool description adds no parameter-specific meaning, so the baseline of 3 is appropriate as no compensation is needed.

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 retrieves the original text and rich text of a message, with the specific qualifier of providing full untruncated content. This distinguishes it from sibling retrieval tools by emphasizing the 'full original' content and the truncation context.

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 explicitly says it is useful when the message's truncationStatus indicates it might be truncated, giving clear when-to-use guidance. It does not name alternative tools or provide when-not guidance, but the use case is directly and appropriately contextualized.

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