gmail_get_message_details

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the description's 'Read-only' is redundant but not harmful. It adds genuine context by disclosing that the body is returned as 'safe Markdown' (sanitized parsing) and that attachments are included in the response.

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 sentences, front-loaded with the action and payload, then the workflow hint, then the safety trait. No 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?

With no output schema, the description usefully summarizes the return shape and the annotations cover the safety profile. Minor gaps remain around attachment handling and error behavior for an invalid ID.

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 single parameter message_id has 0% schema description coverage, and the description never clarifies that it is a Gmail message ID from search results. The implied link to gmail_search_messages gives a weak hint but does not compensate for the gap.

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 and resource ('Fetches one message') and enumerates the parsed payload (headers, Markdown body, attachments). It is distinguishable from gmail_search_messages, though it never contrasts itself with gmail_preview_message or gmail_get_thread_summary.

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?

"Use after gmail_search_messages" gives an explicit workflow position and a named prerequisite tool. It does not state when not to use it, e.g. versus gmail_preview_message for a lighter fetch.

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