Create contacts in bulk

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

Beyond the annotations (readOnlyHint=false, destructiveHint=false), the description discloses key behaviors: background import (success means accepted, not finished), deduplication of existing emails, and double opt-in handling. This adds substantial value, though it omits potential failure modes or rate limits.

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 front-loaded with the main action, followed by three critical behavioral notes. Every sentence adds value, with no redundant or filler content.

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?

The description covers essential aspects for a bulk async import: async acceptance, deduplication, and double opt-in handling. It does not mention error handling for individual contacts or output format, but given the lack of output schema and the tool's simplicity, this is fairly complete.

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 description coverage is 100%, so the baseline is 3. The description itself does not add parameter-specific guidance beyond what the schema already has (e.g., phone format). Some schema descriptions are weak ('name parameter'), but the description does not compensate for those.

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 'Create many contacts in a profile in a single call,' specifying the verb, resource, and scope. It distinguishes this bulk operation from single-contact creation tools by emphasizing 'many' and 'single call.'

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 implies usage for bulk creation ('many contacts') but does not explicitly name alternatives or state when not to use it. There is no mention of reach_createANewContactV1 or other single-contact tools, leaving the choice somewhat to inference.

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