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

With no annotations, the description carries the full burden and does well on cost/limits: it discloses the $0.003 per-call x402 price, the 5,000-URL cap, and the no-sitemap-no-charge rule. It omits error behavior and what happens past the 5,000 cap, which keeps it short of a 5.

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?

A single dense sentence that front-loads the resource and scope, then appends the pricing constraint. No filler, and the cap is stated inline rather than buried.

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 two-parameter read tool with no output schema, the description covers the return contents (URLs plus lastmod), the volume ceiling, and the payment model. Remaining gaps (pagination/truncation at 5,000, failure when no sitemap exists) are minor but real.

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% and both parameters are self-documented (including the x402 payment payload mechanics), so the schema does the heavy lifting. The description adds no further parameter syntax or format detail; baseline 3 applies.

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?

States a specific verb+resource: it returns every URL a site publishes in its sitemaps, and even enumerates the discovery paths (robots.txt, nested indexes, gzip). An agent can distinguish it from content-oriented siblings like site_extract or page_markdown without opening the schema.

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 implies the use case (mapping a site's URL inventory) and adds a cost-triggering condition ('a site without a sitemap is not charged'), but it never says when to prefer this over siblings such as site_extract or web_read, nor any exclusions. Usage is only implied.

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