fetch_url

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

With no annotations, the description carries the full burden. It discloses that only public URLs are supported and that output can be Markdown or text, but it doesn't cover redirects, error handling, content extraction specifics, or rate limits. It provides basic context but lacks richer behavioral detail.

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 captures the core functionality and output options without redundancy or irrelevant details.

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 simplicity and comprehensive schema descriptions, the description is complete enough. It adds the key distinction of 'public' URLs and the output format, which is sufficient for an agent to invoke it correctly.

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 description doesn't need to elaborate on parameters. It adds some semantic meaning by noting 'clean Markdown' which aligns with the output parameter, but the schema already describes all parameters sufficiently.

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 a URL and returns extracted content as Markdown or plain text, using a specific verb and resource. It distinguishes itself from sibling search tools by focusing on direct URL retrieval.

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 use for directly retrieving a known public URL rather than searching, but it doesn't explicitly mention when not to use it or point to alternatives like web_search. This is implied by the sibling tool names and the word 'public'.

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