List TestFlight groups

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the leading "Read-only" sentence merely repeats structured data. The genuinely additive part is the disclosure of what each result shows (internal/external status, public link on/off), which matters since there is no output schema. Pagination behavior via limit/cursor is left to the schema.

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?

Two short sentences, front-loaded and free of filler. The opening "Read-only" is wasted given the annotations, but the rest earns its place by naming the returned attributes.

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 paginated read with full schema coverage, the description supplies the crucial missing piece — what fields each group carries. It omits any mention of paging behavior, but cursor and limit are self-documenting in the schema.

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% — all three parameters (app identifier formats, limit default/max, cursor source) are documented in the schema itself. The description adds no additional meaning about parameters, so baseline 3 applies.

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 ("Lists an app's TestFlight beta groups") and even enumerates the key attributes returned (internal vs. external, public link state), so an agent knows exactly what it gets. It does not explicitly distinguish itself from siblings like list_beta_testers or get_app, which keeps it out of 5 territory.

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 implied by the purpose: fetch the beta groups belonging to a given app. There is no statement of when to prefer this over list_beta_testers, no prerequisites (e.g., does the app need TestFlight enabled), and no exclusions.

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