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

With no annotations, the description still carries the critical behavioral disclosure: this is an irreversible real-world send ('REAL emails to real people'), it bypasses the schedule, and it must be gated by prior user approval. It stops short of describing credit consumption, rate limits, or what happens when `limit` exceeds the number of prepared emails.

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, zero filler, with the irreversible-send warning and the approval precondition front-loaded before any parameter detail. 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 destructive send tool with no annotations and no output schema, the definition covers the essentials an agent needs: irreversibility, schedule override, the approval gate, and the send-count cap. Only secondary operational details (credit cost, partial-failure behavior) are absent.

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 50% — `id` is documented as a campaign UUID from list_campaigns, but `limit` has no schema description. The description conveys the meaning of `limit` ('send up to limit prepared emails') but not its bounds or what happens to unsent emails, so it only partially compensates for the coverage 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 ('Send ... prepared emails'), the override behavior ('immediately, ignoring the schedule'), and scopes it by the `limit` parameter. It is clearly distinguishable from preview_send_campaign_emails_now and schedule_campaign_delivery 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?

Gives an explicit precondition — 'Only after the user approved preview_send_campaign_emails_now' — which simultaneously names the required prior tool and implies the when-not case. The 'ignoring the schedule' clause further routes the agent away from schedule_campaign_delivery for scheduled sends.

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