get_message

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds genuinely useful non-obvious behavior: it returns text and HTML content, and critically that reading does not mark the message read — an effect annotation hints at but does not state.

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?

Three short, front-loaded sentences with no filler: purpose first, then the important side-effect disclosure, then the folder default. Every sentence earns its place.

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 read-only tool with no output schema and annotations covering safety, the description is adequate on behavior and content. The gap is parameter coverage: with 0% schema descriptions, emailId and accountId are undocumented anywhere, which matters for a tool needing to locate a specific message.

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?

With 0% schema description coverage and 3 parameters, the description carries the burden and does not meet it. The only parameter detail given ('folder defaults to inbox') merely repeats the schema's default value, and neither emailId nor accountId is explained at all, so an agent gets no guidance on identifying the message or selecting an account.

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?

States a specific verb ('Read') and a precisely scoped resource ('one owned message including text and HTML'), which distinguishes it from list_messages and search_messages by signaling single-item retrieval. It does not name a sibling explicitly, so the differentiation is implied rather than stated.

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?

'Read one owned message' implies this is the single-item lookup versus the list/search siblings, and the folder default hints at mailbox context. However, there is no explicit when-to-use or when-not-to-use guidance and no named alternative for scenarios like retrieving many messages.

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