bulk_message

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

No annotations are present. The description states the core function but omits behavioral traits such as rate limits, confirmation, error handling for partial failures, or idempotency. For a bulk messaging tool, details about delivery guarantees and failure handling would be valuable.

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?

The description is extremely concise and well-structured: two sentences. The first sentence states the purpose, and the second provides targeting guidelines and constraints. Every word serves a purpose with no redundancy.

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?

Given the complexity (6 parameters, no annotations, but an output schema exists), the description covers the main targeting logic and constraints. It does not explain execution behavior (e.g., asynchronous processing, result format) but the output schema presumably handles that. It could mention potential size limits or batch behavior for completeness.

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?

The input schema has 100% description coverage, so the schema already describes each parameter. The description adds value by explaining the relationship among targeting parameters ('Target by specific IDs, a customer tag, or a platform') and the requirement that at least one is provided. This is helpful but does not provide additional syntax or format details beyond the schema.

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?

The description clearly states the action ('Send a message to multiple customers') and the resource ('multiple customers'). It enumerates specific use cases (promotions, announcements, updates) and distinguishes from sibling tools like 'reply_to_message' and 'send_shipping_info' which are for individual messages.

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?

The description provides clear context for when to use the tool (broadcast promotions, announcements, updates) and includes a key constraint ('At least one of customer_ids, tag, or platform is required'). However, it does not explicitly mention when not to use it or provide direct alternatives, though the sibling list implies that individual messaging tools exist.

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