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

Beyond the annotations (readOnly/openWorld/idempotent), the description discloses a lot the schema does not: the pricing model ($0.002/page), both payment paths (x402 with X-PAYMENT header, or prepaid key via Authorization: Bearer), and the critical billing nuance that you are charged for the requested limit. It does not cover failure behavior, rate limits, or robots/politeness handling, keeping it below 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?

Purpose is front-loaded in the first clause, and every subsequent clause (scope, output, price, payment, trial exclusion) carries distinct information. The semicolon-chained structure is dense, but nothing is redundant.

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 read-only, four-parameter tool with a fully documented schema and no output schema, the description covers scope, cost, and authentication adequately. The main residual gap is the return structure (a single markdown blob vs. a list of pages keyed by URL), which matters for downstream use since no output schema exists.

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 every parameter is already documented, which sets the baseline at 3. The description reinforces the non-obvious cost consequence of 'limit' but adds no syntax or semantics for 'include' or 'maxChars' beyond what the schema states.

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 verb and resource ('crawl a website'), plus the traversal strategy ('breadth-first from a start URL on the same host') and the output form ('clean markdown for up to 50 pages'). It is clearly distinguishable from a URL-mapping or single-page extract tool by implication, but never names the sibling it competes with (e.g. map_site), so full sibling differentiation is left to inference.

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 describes the shape of the operation (whole-host crawl, up to 50 pages) which implies when it fits, and it flags 'Not in the free trial' plus payment requirements. However, there is no explicit when-to-use/when-not guidance and no pointer to an alternative for narrower jobs like scraping one page or just listing URLs.

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