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

Annotations already flag destructiveHint=true and openWorldHint, but the description adds real consequence context those fields cannot convey: the operation acts on all inboxes for the site at once, does not halt outreach, and a long pause on a young inbox harms deliverability later. It does not explain reversibility or what the response contains, so a 4 rather than 5.

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 sentences, front-loaded with the action and scope, followed by sibling differentiation and then the risk caveat. No sentence is filler and the ordering matches how an agent would evaluate the call.

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 two-parameter mutation with no output schema, the description covers scope, side effects on outreach, and deliverability risk. Missing only whether the change is immediately reversible and what confirmation is returned, which are minor for a fully schema-documented 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 coverage is 100%, so the baseline is 3; the description earns a bump by clarifying that the action applies to every inbox the site sends from, which sharpens the meaning of workspaceId scope. The enabled true/false semantics are already documented in the schema, so no additional credit there.

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 concrete verb pair (pause/resume) and resource (warmup for the sending inbox's reputation) with scope ('every inbox this site sends from'). It explicitly distinguishes itself from the sibling set_sending, so an agent can route without opening either schema.

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?

Names the nearest alternative (set_sending) and gives the condition that separates them: warmup mail goes to a warmup network, not prospects. It also clarifies that pausing does not stop outreach, which prevents a wrong inference. It does not spell out when an agent should prefer set_sending instead, so not a full 5.

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