petra402

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

With no annotations provided, the description carries the full burden, and it delivers exceptional transparency: per-call cost, free cache hits, failed scrape not charged, payment at the HTTP transport layer, x402 v2 vs v1 incompatibility, and policy-based refusals. This goes far beyond what the schema alone provides and tells an agent exactly what to expect at runtime.

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 longer than average, but nearly every sentence earns its place: cost, cache, protocol version, and policy refusals are all operationally relevant. The main purpose is front-loaded, and details are organized. It is slightly dense, but not wasteful.

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 tool with no output schema and no annotations, this description is remarkably complete. It tells the agent what the tool returns (main content as markdown), when it is charged, when it is free, what protocol to use, and what will be refused. An agent can invoke this tool correctly without external documentation.

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?

Schema description coverage is 100%, so the baseline is 3. The description reinforces payment/cache behavior relevant to parameters like fresh and max_age_seconds, but it does not add much semantic meaning beyond what the schema already states. The schema itself already documents truncation, cache bypass, and link retention clearly.

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 opens with a specific verb and resource: 'Fetch a public web page and return its main content as markdown.' This unambiguously states what the tool does, and the surrounding payment/policy details make the tool's scope and constraints clear. There are no sibling tools to distinguish against, but none are needed.

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 explicitly states the tool is for public web pages and explicitly lists when it will refuse: government, military, health domains, private/internal addresses, robots.txt-disallowed paths, and anti-bot-protected sites. It also gives critical when/how-to-handle payment behavior, including the x402 v2 protocol warning to avoid infinite 402 loops. This is strong when-and-when-not guidance.

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