web_fetch

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

With no annotations, the description carries the full burden, and it does add noteworthy behavioral context: it explains that HTML is converted to markdown or text, implying content extraction rather than raw HTML delivery. However, it does not disclose error handling, redirects, or authentication concerns, leaving some behavioral gaps.

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, front-loaded sentence that immediately communicates the tool's core function and output format transformation. Every element earns its place, with no redundant phrasing or filler.

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?

The tool is straightforward with a clear schema covering all four parameters, so the description is nearly sufficient. It explains the core transformation (HTML to markdown/text) and output nature (readable content), though it omits details like return value structure or failure modes. Given the simplicity and 100% schema coverage, this is a high degree of completeness.

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 baseline is 3. The description's mention of markdown/text conversion aligns with the extractMode parameter but adds no new details beyond what the schema already specifies. It does not elaborate on maxChars or sessionKey semantics, which the schema already covers.

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 specific action: 'Fetch and extract readable content from a URL', with explicit mention of HTML being converted to markdown or text. This distinguishes it from siblings like web_search (search) and browser (interactive), as it identifies a unique fetch-and-convert operation.

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 for fetching web content, but offers no explicit when-to-use or when-not-to-use guidance, nor does it reference alternative tools. The context from sibling tool names (e.g., browser, web_search) could help an agent infer when this tool is appropriate, but the description itself does not provide that guidance.

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