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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the agent knows this is a safe, idempotent read. The description adds context about returned content but does not disclose additional behavioral traits such as rate limits, failure modes, or authentication prerequisites beyond what the api_key parameter description already explains.

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 that states the trigger condition and then lists the included data categories. It is concise with no wasted words, each part contributing to the tool's purpose.

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?

An output schema exists, so return values are already documented. The description covers the core purpose and content, and parameters are fully described in the schema. It could mention alternatives like getConversation or getThread, but overall it is sufficient for a well-annotated read tool.

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 100%, and both id and api_key have detailed descriptions explaining provenance and usage. The tool description itself does not add parameter-level meaning, so the baseline of 3 applies.

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 action ('get full details') and the resource ('one inbound email ID'), enumerating the included data categories (parsed bodies, threading metadata, SMTP envelope, webhook state, replies). This makes it distinct from sibling tools like getConversation or getSentEmail.

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 opens with 'Use this when you need full details for one inbound email ID,' providing explicit context for when to invoke the tool. It does not name alternative tools or exclusions, but the 'when' phrasing is clear enough to guide selection among siblings.

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