assign_build_to_version

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

Annotations already declare destructiveHint=true, idempotentHint=false and openWorldHint=true, so the safety profile is covered. The description adds real context by requiring a 'processed' build and scoping the mutation to draft state, but it omits the critical behavioral question for a destructive, non-idempotent call: what happens to a build already attached to the version, and whether it is replaced or rejected.

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?

One sentence, front-loaded with the mutation warning and zero filler. It is efficient, though the brevity borders on under-specification rather than tightness.

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 destructive, non-idempotent, open-world mutation with two required undocumented parameters and no output schema, the description is too thin. An agent still cannot tell whether attaching replaces an existing build, what failure modes exist, or what the call returns.

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 0% and neither parameter carries a description, so the description carries the full burden. It adds nothing about versionId or buildId — no indication of what kind of IDs these are, where to obtain them (list_versions / list_builds), or what happens if the build belongs to a different app than the version.

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: attach a processed build to an App Store version. The phrase 'app draft state' scopes it apart from the beta-group sibling add_build_to_beta_group and from add_version_to_submission, though it never names those alternatives explicitly.

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?

Usage is only implied: 'processed build' hints that the build must have finished processing first, and 'draft state' hints this is pre-submission work. There is no explicit when-to-use/when-not guidance and no mention of the sibling tools that handle the nearby cases (beta groups, review submissions).

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