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

With readOnlyHint and openWorldHint already covering safety, the description adds substantial non-obvious context: the cost per page ($0.001/page, $1 per 1,000), the same-site link restriction, and the effect of `query` in pruning to relevant passages. It does not cover authentication or rate limits, but the cost and scoping disclosures are valuable.

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?

Two dense sentences with the tool's action, scope, output format, and cost front-loaded. Every sentence carries useful information and there is no filler.

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 crawl tool with 100% schema coverage and no output schema, the description supplies the key missing context: output is Markdown pages, `query` changes the result shape, and cost is per returned page. It does not describe pagination or failure behavior, but enough is present to call the tool 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 description coverage is 100%, so every parameter is already documented. The description restates the `max_depth` and `limit` caps and explains that `query` ranks and prunes pages, but adds little syntax or meaning beyond what the schema already provides. 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 verb and resource ('Crawl one website from a start URL') and specifies the output format ('get its pages as Markdown'). It also constrains scope ('same-site links only'), making it easy to distinguish from siblings like extract_url for single pages or map for site structure.

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 explains what the tool does and how the `query` parameter changes behavior, but it never explicitly says when to choose this over contextfetch_extract_url or contextfetch_map. Usage is implied by the crawl scope rather than stated as a decision rule.

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