Read Email

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

The annotations (readOnlyHint=true, idempotentHint=true, openWorldHint=true) already convey the read-only, idempotent, and potentially external-state-dependent nature. The description adds the qualifier 'full content', suggesting it returns the complete email rather than a summary, but it does not disclose error handling, folder defaults, or whether attachments are included. This is minimal but not redundant.

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, concise sentence that front-loads the verb and resource. Every word earns its place, with no redundant information 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 simplicity, strong annotations, and well-described schema, the description is minimally adequate but not fully complete. It lacks detail on the return format (e.g., is it raw text, HTML, or structured JSON?) and behavior for missing or invalid UIDs. Without an output schema, the description should clarify what 'full content' means, leaving some ambiguity for the agent.

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 provides descriptions for both parameters (uid and folder) at 100% coverage. The description's mention of 'by UID' adds no new semantic meaning beyond what the schema already states, so the baseline score of 3 applies. No additional parameter details are provided in the 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 'Reads' and resource 'full content of an email' and specifies the key parameter 'by UID', which clearly distinguishes this from sibling tools like list-emails (which lists metadata) and mark-as-read (which modifies state). It is precise and 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?

The description does not explicitly state when to use this tool vs alternatives or provide exclusions. However, the schema description for the uid parameter references list-emails and folder modes, implying a workflow. This is useful context but it resides in the schema, not the description, so usage guidance is only implied rather than explicit.

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