verify_url

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

With no annotations provided, the description carries the behavioral disclosure burden. It transparently states that redirects are followed and that the tool reports live status, final URL, page title, and a text snippet. It does not cover error behavior or timeout handling, but the core behavior is clearly disclosed.

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?

The description is two concise sentences with no filler. The first sentence front-loads the action and outputs; the second sentence gives a concrete use case. Every sentence earns its place.

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?

There is no output schema, so the description helpfully enumerates the returned information: live status, final URL, page title, and text snippet. It covers the required URL, optional timeout, and optional phrase check. It could be more complete about failure modes or non-HTML responses, but for a simple fetch-and-verify tool it is largely sufficient.

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 the schema already documents all parameters. The description adds useful context for expect_contains ('check that the page contains an expected phrase') and timeout defaults are already in the schema, but it does not add substantial new parameter meaning.

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 clearly states a specific action ('Fetch a URL'), the resource, and the key outputs: live status, final URL, page title, and text snippet. It does not explicitly differentiate from sibling tools like verify_claim, but the URL-focused scope makes the purpose unambiguous.

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 gives an explicit use case: 'Use to verify claims like "the post is live" or "the page says X".' This tells an agent when to reach for the tool, though it does not mention when not to use it or name alternatives.

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