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

Annotations already declare the tool read-only, idempotent, and non-destructive. The description adds meaningful behavioral context beyond those hints: it targets only public URLs, returns a specific set of fields, and operates on a pay-per-success basis, which signals cost implications the annotations do not cover.

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-loads the action, and includes no filler. Every phrase adds useful information about the tool's behavior and design context.

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 description covers the primary input, output fields, and pay-per-success framing, but it omits important context such as how the output format parameter works, what failure or pricing caveats exist, and how this tool relates to its siblings. The output schema reduces the need to enumerate return values, but usage and parameter edge cases remain incomplete.

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 only 33% schema description coverage, the description needed to compensate by explaining parameters such as 'output' and 'max_price_usdc', but it does not. It lists extraction result fields rather than parameter meaning, and 'pay-per-success' only hints at the cost parameter without explaining its role or constraints.

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 uses a specific verb ('Fetch one public URL') and identifies both the resource and the return payload, making the core purpose clear. It does not explicitly differentiate from sibling tools like enrich_domain_result or quote_data_result, so it stops short of a 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 phrase 'Designed for pay-per-success agent extraction' implies when this tool is appropriate, but there is no explicit guidance on when to choose it over siblings or when to avoid it. Usage context is implied rather than directly stated.

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