List Usage

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

Annotations already declare readOnlyHint=true and destructiveHint=false, covering safety. The description adds the fields returned and the purpose, but does not disclose additional behavioral traits such as pagination, ordering, or rate limits beyond what is in the schema. It provides moderate extra context.

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?

Two concise sentences: the first describes what the tool does, the second explains its use case. No unnecessary words, and the key information is front-loaded.

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 lists the returned fields and the use case, which is sufficient for a read-only list tool with a well-documented schema. It lacks mention of pagination or filtering limitations, but these are covered by the schema. The description is largely complete given the context.

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?

Input schema coverage is 100% with clear descriptions for all 5 parameters. The description does not add new meaning to the parameters beyond what the schema provides, so it meets the baseline level for high schema coverage.

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 states the verb 'List' and the resource 'per-scan usage rows', listing the fields returned. It distinguishes from siblings like 'list_usage_summary' by emphasizing granular per-scan data and a specific use case: attributing cost to scans or campaigns.

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 clear use case ('Use to attribute cost to specific scans or campaigns'), indicating when to use this tool. It implies that for aggregated cost data, other tools (e.g., get_usage_summary) should be used, but does not explicitly name alternatives or state when not to use.

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