Fetch URL

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

With no annotations, the description carries the full burden of behavioral disclosure. It adds non-obvious information about rotating across multiple extraction providers and failover behavior, which helps an agent anticipate reliability and latency characteristics. It does not mention error handling or rate limits, but those are less critical for a simple fetch operation.

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 a single sentence that states the primary purpose first and then adds the key behavioral detail about provider rotation and failover. There is no filler or redundant repetition of the tool name.

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 tool with one required parameter and no nested structures, the description is largely complete: it explains the input (URL), the output (markdown content), and the notable internal behavior (provider failover). It could mention what happens on fetch failures, but this is a minor gap given the tool's simplicity.

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 already fully documents the only parameter, 'url', with a description ('URL to fetch'). The tool description adds no additional parameter-level meaning, so the baseline score of 3 applies.

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 action ('Fetch a web page') and a resource (a URL), and clarifies the return format ('content as markdown'). This clearly separates it from sibling tools like web_search, which searches rather than fetches a specific page.

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 implies when to use the tool: when you have a specific URL and want its content as markdown. However, it does not explicitly state when not to use it or mention alternatives such as web_search for discovery or engine_status for checking provider health.

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