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

There are no annotations, so the description carries the full behavioral burden. It usefully discloses that the tool itself is free and charges nothing, which is a meaningful cost-safety signal. But it doesn't say whether it hits the network, whether results are cached, or what the response shape looks like. Some value added, incomplete for zero-annotation coverage.

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?

Three short clauses: what it lists, the specific catalog, and the free/no-charge note. Every sentence earns its place and the scope 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?

For a zero-param discovery tool with no output schema and no annotations, the description tells the agent what endpoints exist and that it's free, but doesn't describe the return format (JSON? list? fields like price, url, pay instructions) or how to actually use the returned pricing. It's adequate but leaves the agent guessing about the payload.

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 takes zero parameters, so per the rules the baseline is 4. The description appropriately spends no space on parameter details and instead front-loads what the tool returns, which is the right allocation for a parameter-free endpoint.

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 and resource — it lists paid x402 endpoints — and enumerates exactly which three (TokenSafe, PoolScan, PromptVault) with sub-scopes like quick/full reports. This is far more specific than the sibling tokensafe_free, making the distinction immediate.

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?

There is implied usage: an agent would call this to discover paid endpoints and how to pay for them. However, it never says when to use this versus the sibling tokensafe_free, nor does it frame the trigger as a conditional ('call this first if you need pricing'). Useful but not fully routed.

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