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

Beyond the annotations, the description discloses authentication requirements, free quota limits per IP and globally, shared ASN pool limits, paid upgrade behavior, and x402 billing options. These are substantial operational details an agent needs before calling the 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 front-loads what the tool returns, then covers billing, auth, scope, and quotas. It is reasonably compact, though the ordering jumps between output, paid access, auth, usage scope, and rate limits.

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 single-parameter read-only tool with no output schema, the description covers return content, scope, auth, quotas, and paid access options. Nothing essential for correct invocation appears to be 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?

Schema coverage is 100% for the single url parameter, which already documents that it accepts one public HTTP(S) URL. The description reinforces the single-URL constraint but adds little parameter-level detail beyond the schema, so baseline 3 is appropriate.

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 resource and return values: title, Open Graph tags and page metadata for one URL. It distinguishes scope from batch/monitoring work, though it does not name sibling alternatives such as read_url or extract_article.

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?

It explicitly says to use for one URL and not for batch work or unrestricted monitoring, giving clear when-to-use and when-not-to-use guidance. It does not name alternative tools for batch or monitoring use cases.

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