App Sync Spec

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

Annotations already declare readOnlyHint=false, idempotentHint=true, destructiveHint=false and openWorldHint=false. The description adds real value on top: it discloses that String Catalogs are destructively pruned to locales.app, and that writes are local-only — details the annotations do not express.

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?

Three tight lines with the action front-loaded and the usage condition immediately after. 'Returns: {ok, files}' is mildly redundant given an output schema exists, which is the only thing keeping it from a 5.

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 single-parameter, idempotent local-write tool with an output schema and full annotation coverage, the description supplies the trigger, the scope, and the destructive pruning caveat. Nothing essential for correct invocation is missing; naming an alternative sibling would make it 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?

There is a single required parameter with 100% schema description coverage, including a format example (/Users/me/Apps/MyApp), so the schema carries the full burden. The description adds no path or format guidance beyond it, making the baseline 3 appropriate.

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 names a specific verb (Regenerate) plus the exact artifacts produced (AppSpec.swift, PaywallSource.swift, Configuration.storekit) and an additional pruning action, so the agent knows precisely what the tool does. It does not, however, distinguish itself from nearby siblings such as storekit_generate, which an agent might reasonably confuse with the Configuration.storekit output.

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?

'Use when: after editing app.spec.json' gives an explicit trigger condition, and 'Local writes only' scopes the operation. It stops short of naming when NOT to use it or pointing at a sibling (e.g. storekit_generate) as the alternative, so it is clear context without exclusions.

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