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

Beyond the annotations (read-only, idempotent), the description adds meaningful behavioral details: Apple's ~200 id round-trip limit, Google's fan-out/coalescing, the response shape difference ('apps' array vs 'app' object), and the store='both' constraint. This significantly enriches the agent's understanding.

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 two sentences, front-loaded with the core action, and every clause conveys useful information without redundancy. It is efficient and well-structured.

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 covers the essential operational context: how to invoke single vs batch, the response shapes, and the store='both' restriction. With the schema providing parameter details and annotations covering safety, the description is complete for this tool's complexity.

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?

The schema already describes all five parameters (100% coverage), so the baseline is 3. The description adds value by explaining the relationship between bundleId and ids, clarifying that store='both' is only supported for batch lookups, and providing a concrete bundleId example, which goes beyond the schema.

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 states a specific verb ('Resolve'/'fetch') and resource ('apps'), and clearly distinguishes the batch capability from the single lookup by bundleId. It explicitly mentions the dual mode (single vs batch) and the store='both' option, differentiating it from sibling tools like get_app.

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 batch lookups (when fetching many apps at once) versus a single bundleId lookup, and notes the Apple/Google fan-out behavior. However, it does not explicitly name alternative tools or state when not to use this tool, so it stops short of the highest bar.

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