Get message content

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

With no annotations, the description carries the full burden of disclosing behavioral traits. 'Fetch' implies a read operation, but the description does not address potential side effects (e.g., marking the message as read), authentication requirements, rate limits, or error behavior. This is a significant gap for a tool that accesses message content.

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, tightly-worded sentence that conveys the core purpose without any filler. It is front-loaded with the verb and resource, making it easy to parse quickly.

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 tool with no output schema and no annotations, the description leaves important gaps: it doesn't describe the return format beyond 'parsed content', doesn't clarify the mailbox parameter, and offers no usage context. The simplicity of the tool raises the bar for clarity, and this description falls short of being fully self-contained.

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 0%, so the description must compensate. It mentions 'by UID', which references the uid parameter, but does not explain the mailbox parameter (default INBOX) or clarify the format/scope of UID. The description adds minimal semantic value beyond the schema.

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 ('single message'), clearly distinguishing the tool from siblings that list or search messages. The qualifiers 'full parsed content' and 'by UID' make the function unambiguous.

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?

No explicit guidance is provided about when to use this tool versus alternatives like list_messages or search_messages. The description implies that a UID is needed, but it doesn't state that users should first list or search to obtain a UID, nor does it mention any exclusions.

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