mcp-fetch

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively describes the two-phase protocol (start/continue), chunked streaming behavior, and various operational parameters like timeout, delays, and proxy support. It doesn't mention rate limits or authentication requirements, but covers most key behavioral aspects.

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 well-structured with clear sections (use cases, protocol, args, returns) but could be more concise. Some information is repeated (e.g., chunked streaming mentioned in both use cases and protocol), and the parameter list includes some redundant formatting. Overall, it's efficiently organized but not maximally concise.

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?

Given the complexity (15 parameters, 0% schema coverage, no annotations) and the presence of an output schema, the description provides comprehensive context. It explains the tool's purpose, usage scenarios, operational protocol, parameter semantics, and return structure, making it complete enough for effective use despite the lack of structured documentation.

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?

With 0% schema description coverage and 15 parameters, the description provides excellent parameter context. It explains the purpose of key parameters (url, to_markdown, wait_selector), categorizes them as required/optional/cursor parameters, and gives semantic meaning to many parameters that would otherwise be undocumented.

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 the tool fetches/crawls dynamic web pages and converts them to Markdown, specifying support for JavaScript rendering. It distinguishes from the sibling 'http_request' tool by emphasizing dynamic content handling and chunked streaming for large pages.

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 explicitly lists three use cases (crawling modern web pages, getting JavaScript-rendered content, downloading large content via streaming) and outlines a two-phase protocol. It provides clear guidance on when to use this tool versus alternatives by highlighting its unique capabilities.

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