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

Annotations already establish that this is a non-destructive read operation. The description adds valuable behavioral context beyond those annotations by specifying that results are summaries, not row data, and that the scope is the account. This is sufficient for a zero-parameter read-only listing tool.

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 a single, well-structured sentence that leads with the action and resource, then adds the key qualifier about summaries. Every word earns its place with no redundant filler.

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 zero-parameter, read-only list operation with an output schema available, the description provides complete context: it identifies the resource type, the account scope, and the summary-only nature of the result. Nothing an agent needs to decide whether to call this tool is missing.

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 tool has zero parameters and the input schema is empty, so there is no parameter information for the description to clarify. The description correctly focuses on the tool's result semantics rather than inputs, earning the baseline score for a no-parameter tool.

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 uses a specific verb ('List') and identifies the resource ('uploaded custom-data (CSV) datasets for the account'). The clarifying clause 'summaries without the row data' distinguishes this listing tool from data-retrieval tools like get_custom_data, making its scope unambiguous.

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 implies when to use the tool: when a summary-level list of uploaded custom-data datasets is needed rather than the row data itself. However, it does not explicitly name alternatives such as get_custom_data or state when not to use this tool, leaving the routing decision partly implicit.

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