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

With no annotations provided, the description carries the full behavioral burden. It transparently discloses the pricing model ($0.05), authentication requirements (no account/API key), the x402 payment flow, the maximum 500 results, and filterability. It stops short of describing error cases or the exact response structure, but given no output schema exists, the disclosure is solid.

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?

Every sentence in the description contributes unique information: core purpose, pricing, payment flow, result limit, filtering, and usage intent. It is front-loaded with the main purpose and remains compact with no fluff.

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?

Given the tool has only 3 optional parameters and no output schema or annotations, the description covers all essential aspects needed for correct invocation: how to call, why to call repeatedly, what to expect (up to 500 changes, filters), and payment handling. Nothing relevant appears 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 schema covers 100% of parameter descriptions, so the baseline is 3. The description adds value beyond the schema by explaining the payment call flow, clarifying that 'payment' is the x402 header, and specifying that the feed supports time-window and protocol filtering, which enriches the semantic understanding of the parameters.

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 tool's function: it is a change feed of recently added, changed, or newly dark endpoints. It specifies the exact resource (endpoints) and differentiates itself from sibling tools like search_agents or get_agent_profile, which focus on other aspects.

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 explicit call sequencing: first call without 'payment' to get requirements, then call with 'payment' to be served. It also mentions the intended repeated usage instead of re-crawling the index, giving clear context. However, it does not explicitly state when not to use this tool versus alternatives.

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