beta_groups__beta_testers__add

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

Annotations already indicate this is a write operation (readOnlyHint=false), non-idempotent, and non-destructive. The description adds the key constraint that testers must already exist ('existing'), which is useful. It does not, however, disclose what happens if a tester is already in the group or mention any required permissions, leaving some behavioral ambiguity.

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 a single, front-loaded sentence that captures the essential purpose, followed by the endpoint reference. No redundant information is included. It is appropriately concise for the tool's simplicity.

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 is sufficient for a straightforward relationship-add operation, especially with detailed schema and annotations. However, it does not explain the response (no output schema exists), error conditions, or whether duplicate additions are allowed. Given the complexity of the nested body and the potential for user errors, a bit more context on expected outcomes would improve completeness.

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 both parameters well-described: 'id' is the group ID from a matching list call, and 'body' is a JSON:API request body with a data array of tester IDs. The description repeats only the high-level concept of adding existing testers, which aligns with the schema. No additional parameter semantics are provided beyond what the schema already states.

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 action: 'Add existing beta testers to a TestFlight group', specifying the verb, resource, and target. The included endpoint further clarifies the operation. It distinguishes from siblings like beta_groups__beta_testers__remove and beta_groups__builds__add by explicitly mentioning beta testers and the group relationship.

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 its use case: when you need to add existing beta testers to a specific TestFlight group. However, it does not provide explicit guidance on when not to use it, such as when creating new testers (beta_testers__create) or when adding groups to testers (beta_testers__beta_groups__add). The usage context is clear but undocumented alternatives are absent.

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