reach_createContactsInBulkV1

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

The description discloses critical behavioral details: the import runs in the background (success response only means accepted, not finished), emails already existing in the profile are left unchanged, and if double opt-in is enabled, new contacts start pending and receive a confirmation email. Since no annotations are provided, this description carries the full burden of behavioral disclosure and does so well, though it omits auth or error handling.

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 concise and well-structured: a single opening sentence states the core purpose, followed by two tightly focused sentences on async behavior, deduplication, and opt-in implications. There is no redundancy or filler.

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 tool's moderate complexity (bulk create with async behavior), the description covers the most important operational aspects: acceptance semantics, deduplication, and double opt-in. It could mention how to verify import completion or error handling, but the core context is sufficient for an agent to understand the tool's behavior.

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 schema already provides descriptions for all parameters, and the tool description adds meaningful behavior for the contacts parameter: deduplication on existing email and double opt-in handling. Some schema descriptions are tautological (e.g., 'contacts parameter'), but the tool-level context compensates for these gaps.

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 tool's function: 'Create many contacts in a profile in a single call.' It specifies the verb (create), resource (contacts), and scope (in a profile). However, it does not explicitly differentiate from sibling contact-creation tools like reach_createNewContactsV1, so it falls short of a 5.

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 phrase 'Create many contacts' and 'in a single call' implies the tool is intended for bulk operations, providing clear context for when to use it. There is no explicit when-not-to-use guidance or naming of alternative tools, but the primary use case is evident.

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