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

Beyond the safety annotations, the description adds critical behavioral context, specifically the price point (0.01 USDC/query) and the mechanism ('Platform-executes funding'), which is essential for an agent making financial decisions.

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 highly concise and well-structured. It front-loads the primary function, provides a specific example/price, and explains the intended outcome in three efficient segments.

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?

Given the high schema coverage and specific instructions, the description provides sufficient operational context—namely, what the funding is for and what the cost is—without needing to elaborate on technical schema details.

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?

While the schema specifies the session ID, the description provides crucial context by mentioning a specific 'Listing: samsungwatch.' This informs the agent about the specific domain of data that this funding mechanism applies to.

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 defines the purpose as buying per-query access to live data. It links this financial transaction directly to the ability to perform data_session_query, leaving no ambiguity about the tool's function.

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 a helpful context by mentioning the 'data_preview' tool as a free alternative for initial testing. However, it does not explicitly guide the agent on the difference between using this function and other potential funding mechanisms (e.g., packages).

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