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

With no annotations, the description carries the full burden of disclosing behavior. It does disclose that the call is FREE, that the list is 'currently registered' (suggesting a live snapshot), and that results are scoped to Base and MAX_PRICE_USD. It does not describe return format, ordering, pagination, or rate limits, leaving notable gaps for a read-only list 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 just two short sentences with no wasted words. 'FREE.' is front-loaded and the action verb 'List' appears immediately. It avoids repeating the title and conveys the core information efficiently.

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 explains the source and scope but not what the returned items look like or how to consume them. An agent knows it will get a list of discovered APIs but cannot tell whether entries are endpoint URLs, names, IDs, or prices, and gets no guidance on ordering or output shape. This is a moderate gap.

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 an empty schema, so the baseline is 4. The description references filters like Base and MAX_PRICE_USD, but these are internal constraints rather than call arguments. There are no parameter meanings to add beyond what the schema already trivially covers.

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 states a specific verb ('List') and resource ('x402dispatcher APIs') and narrows the scope with 'Bazaar discovery (Base, within MAX_PRICE_USD)'. This makes the tool's basic function clear and distinguishes it from siblings like list_verified_apis. However, terms like 'Bazaar discovery' and 'MAX_PRICE_USD' are left unexplained, so the purpose isn't fully self-contained.

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?

No explicit when-to-use guidance is provided. The description does not differentiate this from the closely related sibling list_verified_apis or mention alternative tools. An agent must rely on the name 'discovered' to infer this is for unverified APIs, which is implied rather than stated.

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