read_url

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

With no annotations, the description must convey behavioral traits. It discloses that the tool is paid with a specific cost, which is good. However, it does not mention error handling (e.g., what happens if the URL is invalid or the page is inaccessible), rate limits, or other non-obvious behaviors.

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 only two sentences long, with no wasted words. It front-loads the core purpose, then adds the distill option and usage context. Every sentence adds value.

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 simple tool with 2 parameters and no output schema, the description covers the basics: what it does, what it returns, and when to use it. However, it omits details like supported URL schemes, maximum page size, or error scenarios. It is adequate but not comprehensive.

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?

The input schema has 2 parameters with 0% description coverage. The description explains the 'distill' parameter ('distill=true adds key-fact bullets') but does not explain the 'url' parameter beyond the tool's general purpose. Since schema coverage is very low, the description should provide more parameter-level detail, especially for the required 'url'.

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 uses a specific verb 'Fetch' and resource 'public web page', and clearly states the return format (title + clean markdown) and an optional distill mode. It distinguishes from sibling tools by focusing on web page retrieval, though it doesn't explicitly compare to similar tools like 'extract'.

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 provides a clear usage context: 'Useful when you have no web access of your own.' It also mentions the cost, which helps the agent decide whether to use it. However, it does not specify when not to use it or suggest alternatives.

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