Send Message Blast

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

Annotations already flag destructive/openWorld/non-idempotent, but the description adds real context beyond them: immediate send, EU marketing-consent filtering, failure when no recipient qualifies, SMS from an automated no-reply number, and consumption of the plan's text allowance. It does not describe the response payload or what partial delivery looks like, which keeps it short of a 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?

Front-loaded with the core action, then layering consent, SMS limits, the estimate recommendation, and plan requirements in a compact block. Dense but each sentence carries a distinct operational fact; a slightly tighter phrasing of the Booksy UI reference would earn a 5.

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?

No output schema exists, yet the description still tells the agent what failure looks like (fails when no client can receive) and steers to estimate_message_blast for counts/cost. It stops short of describing success response shape or partial-send outcomes, leaving a small gap for a destructive bulk-send 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%, including the channel enum, subject default, and client_ids source, so the schema does the heavy lifting. The description adds only the indirect constraint that client_ids must be consent-eligible, which is a behavioral rather than a parameter-format clarification.

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+resource (send one Message Blast to listed clients via email/SMS/push) and ties it to the concrete product path (Promotion > Message Blasts > Create your own message). It is clearly distinguishable from siblings like estimate_message_blast and list_message_blasts, which are named or implied.

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 directs the agent to run estimate_message_blast first for count/cost, states the paid-plan prerequisite (free trial refuses one-time messages), and gives the failure condition (call fails when no listed client can legally receive). That covers when to use, prerequisites, and the adjacent alternative.

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