assign_build_to_group

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

With no annotations provided, the description discloses important behavioral traits: it defaults to the newest processed build, requires confirm:true, and warns that Apple notifies every tester immediately with an irrevocable notification. It also notes the Pro feature requirement. This goes beyond just stating the action.

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 three short, focused sentences: purpose, required confirmation with consequence, and licensing note. Every sentence provides essential information without any fluff.

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 mutating tool with no output schema, the description covers key aspects: purpose, default behavior, required parameter value, irreversible side effect, and feature restriction. It could mention what happens on failure or whether existing assignments are replaced, but overall it is quite 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?

Although schema descriptions cover 100% of parameters, the description adds meaning by clarifying that confirm must be set to true ('Needs confirm:true'), which is not clearly indicated in the schema's required fields. It also reinforces the build_id default behavior.

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: 'Assign a build to a TestFlight beta group so testers can install it'. It also mentions the default behavior (newest processed build), which distinguishes it from related operations like attaching a build elsewhere or inviting individual testers.

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 (to make a build available to a beta group) and a critical prerequisite (confirm:true). It doesn't explicitly mention alternatives or exclusions, but the context is sufficiently clear, and the 'Pro feature' note adds a usage restriction.

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