gmail_message_actions

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

With no annotations, the description carries the burden, and it does volunteer 'Read-only' plus the downstream applicability of the block/unblock/unsubscribe/phishing tools — useful context. However, it does not disclose that the tool navigates the UI (opening a conversation, honoring stay_open/keep_unread), so the 'read-only' framing is narrower than the actual behavior, and no auth/rate/return-shape info is given.

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?

Two tight sentences: the primary purpose leads, followed by a single clarifying line on the read-only guarantee and the dependent tools. No waste or repetition.

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?

The definition covers purpose and read-only status but leaves gaps for a 7-parameter, annotation-free tool: how the UI navigation side effects work and what the returned action list looks like (no output schema) are unaddressed. Adequate but incomplete.

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 all 7 parameters are documented in the schema (index, query, folder, message_index, stay_open, keep_unread, expect_subject). The description adds no parameter detail, 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?

States a specific verb and resource — enumerating the actions a message's own menu offers — and gives concrete examples (Reply all, Forward, Block, Report spam). It is distinguishable from action-executing siblings like gmail_block_sender because it frames itself as a query, though it never explicitly names a sibling to differentiate against.

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?

Usage is implied: call this to learn whether gmail_block_sender / gmail_unblock_sender / gmail_unsubscribe / gmail_report_phishing apply to a message. That is a clear enough trigger, but there is no explicit when-not guidance or routing to gmail_read / gmail_open for other purposes.

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