Assign contacts to a tag

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

The description discloses key behavioral traits beyond the annotations: the work is queued, a success response means accepted rather than finished, and already-tagged contacts are left alone. This gives an agent an accurate model of side effects and asynchronous behavior. No contradiction with annotations.

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 compact sentences, no filler, and the core purpose is in the opening line. The target-selection options and queueing behavior are presented in a natural order.

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 bulk mutation tool with no output schema, the description covers the essential facts: target selection, asynchronous acceptance, and idempotent behavior for already-tagged contacts. The annotations supply the read/write and destructive hints, so nothing critical is missing.

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%, and the description adds meaningful semantics beyond it by explaining the relationship between contact_uuids and all_contacts and their targeting behavior. The required profileUuid and tagUuid remain lightly described in the schema, but their meaning is self-evident from context.

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: 'Assign a tag to many contacts at once.' The 'many contacts at once' phrasing distinguishes this from single-contact and removal siblings like reach_assignAContactToATagV1 and reach_removeContactsFromATagV1. No ambiguity about what the tool does.

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?

Provides clear within-tool usage guidance: pass contact_uuids for specific contacts or all_contacts for every contact in the profile. It does not explicitly mention sibling alternatives or when not to use this tool, but the 'many contacts at once' wording implicitly scopes it for bulk assignment.

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