MCP Web Tools

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 mentions the tool returns 'raw text content' and hints at use cases, but fails to disclose critical traits like error handling (e.g., for invalid URLs), authentication needs, rate limits, or performance considerations. This leaves significant gaps for a tool that interacts with external web resources.

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 appropriately sized and front-loaded, consisting of two concise sentences that directly state the tool's function and its return value. Every sentence earns its place by providing essential information without redundancy, making it efficient and well-structured.

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 tool's moderate complexity (fetching web content) and the absence of annotations and output schema, the description is partially complete. It covers the basic purpose and return type but lacks details on behavioral aspects, error handling, and output structure. This makes it adequate as a minimum viable description but with clear gaps in context.

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 100% description coverage, clearly documenting both parameters ('url' and 'timeout'). The description adds no additional meaning beyond the schema, as it doesn't elaborate on parameter usage or constraints. According to the rules, with high schema coverage (>80%), the baseline is 3, which applies here since the description doesn't compensate with extra insights.

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's purpose with a specific verb ('fetch') and resource ('content of a web page'), and distinguishes it from sibling 'web_search' by focusing on retrieving raw text from a given URL rather than searching. However, it doesn't explicitly differentiate from potential siblings like 'web_scrape' or 'web_metadata', keeping it at 4 instead of 5.

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 usage by stating it's 'suitable for reading articles and documentation,' suggesting contexts like content extraction. However, it lacks explicit guidance on when to use this tool versus alternatives (e.g., 'web_search' for broader queries) or any exclusions (e.g., not for dynamic pages), leaving usage somewhat inferred rather than clearly defined.

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