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

No annotations are provided, so the description carries the burden. It discloses that the tool is free to call and returns live prices, which is transparent for a read-only listing. However, it does not address output format or behavior when no paid capabilities exist.

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?

Single sentence with zero waste, front-loaded with the action and entity. Every clause adds value: paid capabilities, live x402 price, network, and free.

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 tool with no output schema, the description adequately explains the return value (list of paid capabilities with prices). However, it could be more complete by explicitly differentiating from palmyr_capabilities to aid tool selection.

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?

Tool has zero parameters, so baseline is 4. The description adds context about what the listing includes (paid capabilities, USDC pricing) beyond the empty 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 clearly specifies the action ('List'), the resource ('every paid Palmyr capability'), and the price context ('live x402 price (USDC on Solana/Base)'). It distinguishes from siblings by focusing specifically on paid capabilities and pricing.

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?

Implied usage as a pricing lookup, but no explicit guidance on when to use this tool vs sibling palmyr_capabilities or i402_plan. The note 'Free — no payment required' provides a usage hint but no exclusions.

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