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

With no annotations, the description carries the full burden. It discloses the 0.01 USDC cost on Base, a key behavioral trait, and notes it works on public URLs, implying no auth needed. It does not detail error handling or limits, but the essential behaviors are covered.

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 two sentences, front-loaded with purpose and output, followed by the parameter guidance and cost. Every word earns its place—no redundancy or fluff.

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 one-parameter fetch tool, the description covers purpose, parameter format, cost, and output type. It does not mention limitations like content size or redirect behavior, but the tool's simplicity and the absence of an output schema make this adequately complete.

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 schema provides no parameter description, so the description compensates by explicitly saying 'Pass the target as url (http/https)', which gives the format and valid scheme for the url parameter. It adds meaning beyond the raw schema, though it does not elaborate on encoding or validation.

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 any public URL and returns a clean, readable markdown or JSON extract. The verb 'Fetch' plus the resource 'URL' is specific, and it distinguishes itself from the sibling crypto/YouTube tools by its general web-fetching purpose.

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?

It provides clear context: the tool fetches any public URL and the url parameter must be an http/https target. It does not explicitly mention when not to use it or name alternatives, but the sibling tools are unrelated domains, so the use case is well implied.

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