reach_assignAContactToATagV1

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

With no annotations, the description carries the burden of behavioral disclosure. It covers two key behavioral traits: immediate execution (rather than queued) and idempotency ('succeeds without duplicating it'). It does not mention permissions, errors, or return format, but the disclosed behaviors are valuable and relevant for a mutation operation.

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 two sentences long, front-loaded with the primary purpose, and includes only relevant behavioral details. Every sentence earns its place with 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?

For a simple mutation with three parameters and no output schema, the description provides the core context: single-contact scope, immediate execution, and idempotency. It adequately differentiates from the bulk sibling and covers the most important behavioral edge case (duplicate assignment). It could be more thorough about errors or permissions, but is sufficient for this simplicity level.

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%, with each parameter having a basic description (e.g., 'Tag uuid parameter'). The tool description does not add additional parameter-level semantics beyond clarifying the roles of tag and contact in a single contact assignment. Baseline 3 is appropriate given the high schema coverage.

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 starts with 'Assign a tag to a single contact,' clearly stating a specific verb and resource. It distinguishes itself from the bulk endpoint by emphasizing 'single contact' and 'Unlike the bulk endpoint,' which sets it apart from sibling tools like reach_assignContactsToATagV1.

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?

It explicitly contrasts with the bulk endpoint ('Unlike the bulk endpoint this is applied immediately rather than queued'), giving the agent a clear behavioral reason to choose this tool for single, immediate assignments. This directly addresses when to use this tool versus alternatives.

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