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

Annotations declare destructive/non-idempotent/open-world, and the description adds context those do not carry: the destination folder, that origin is noted, the required read+modify scopes, and the cost model ('paid (cancel free)'). That is meaningful behavioral disclosure beyond the structured hints.

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 dense sentences, front-loaded with the core action and scope before the reversal and permission details. No wasted words, though the cost/permission clause is slightly tacked on.

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 need not be explained. The description covers scope, destination, reversal, permissions, and cost, leaving only the when-to-use-vs-alternatives dimension thin.

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 coverage is 86%, so the schema already documents nearly every parameter. The description adds only a little (cancel=true is the reversal switch, until is the target time), which is consistent with the baseline 3 when the schema does the heavy lifting.

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 ('Moves one message') plus a crucial scope qualifier ('not its thread') and the destination ('mailmcp-snoozed'). An agent can distinguish this from sibling mutation tools like modify_message or trash_message immediately.

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?

Explicitly names the reversal path ('wake_snoozed or cancel=true brings it back'), giving clear guidance on how to undo. It does not, however, say when to prefer snoozing over related scheduling tools like set_followup, so it stops short of full when/when-not guidance.

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