Verify whether a site's robots.txt permits fetching a given URL and return any crawl-delay rule. Runs through the browser so it follows the configured proxy.
Check whether robots.txt on the URL's site allows fetching it (and any Crawl-delay). Loaded through the browser, so it follows the configured proxy.
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | ||
| user_agent | No | * |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful context beyond that: the check is loaded through the browser and therefore follows the configured proxy, which affects what rules are actually returned.
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 short sentences, front-loaded with the core action and followed by the one non-obvious behavioral detail. Nothing is wasted.
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?
An output schema exists, so return values need no explanation, and the proxy/browser context is disclosed. However, the undocumented user_agent parameter leaves a real gap for a tool whose result is user-agent dependent.
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 0% for two parameters. The description implies the required url is used to derive the site, but it never explains the user_agent parameter or the fact that the effective rules depend on it (default '*'), which is the key semantic for a robots check.
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 and resource: checks robots.txt for the site of the given URL, and notes it also surfaces Crawl-delay. This is clearly distinct from siblings like read_url or navigate, though it doesn't name a sibling explicitly.
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?
Usage is implied (check before fetching a URL) but never stated as a when-to-use rule, and no alternative or exclusion is given. An agent can infer the context but must do the work itself.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.