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

Annotations already declare read-only, idempotent, non-destructive behavior. The description adds free-guest access, a query quota, and pricing context, but saying both 'Price 0.01 USDC/query' and 'FREE preview — no key, no payment' creates billing 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 repeats the no-key/no-payment message across multiple sentences and uses promotional emoji/call-to-action phrasing. The actual preview purpose is buried under marketing language.

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 read-only preview with two optional parameters, it gives enough context to try a sample question. It omits what the preview returns (public metadata only) and how it relates to the paid session-query tools, leaving the agent to infer.

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%, so the schema already explains both parameters. The description adds sample questions that demonstrate the question field and names the samsungwatch slug, but it adds no syntax or format details 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 signals a free preview of the samsungwatch listing and provides sample questions, but it never states a clear verb/resource like 'returns public metadata' and does not distinguish the operation from data_session_query. The marketing call-to-action obscures the actual purpose.

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?

It tells agents to call now with no key or payment and mentions a 20-queries/session limit, implying when the free preview is appropriate. However, it names no alternative such as data_session_query and gives no explicit when-not guidance.

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