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

Adds substantial context beyond annotations: no page is rendered, nothing is charged, no x402 challenge, and the returned number matches what the unpaid call puts in its 402. It also explains what request_fingerprint does (binds the price). The safety/behavior profile is richer than readOnlyHint/idempotentHint alone.

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?

Front-loads 'FREE preflight' and the core behavior, with zero wasted sentences. Slightly over-stuffed with em-dash asides and a raw HTTP-equivalent string, which is minor bloat but informative.

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?

With no output schema, the description fully documents the return payload (pages found/billed, tier split, totals, fingerprint) and the cost/side-effect story. For a read-only preflight, an agent has everything needed to call it correctly.

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 0% and both url and sitemap_url are undocumented in the schema. The description only says 'Same input as access_crawl', which defers meaning to a sibling and does not explain the distinction between url and sitemap_url or why neither is required. That is a real gap for a tool whose only parameters are undocumented.

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 ('FREE preflight for access_crawl') and precisely what it returns: tiered price preview with pages found, pages billed, tier split, totals, plus a request_fingerprint. It is clearly distinguished from the sibling access_crawl (which performs the paid, rendering call).

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 gives clear context for use: call this before the paid call to preview price, and 'no payment required: call directly without payment'. The relationship to access_crawl is explicit ('same input'). It stops short of explicit exclusions (there is no 'don't use this to actually crawl' statement), so 4 rather than 5.

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