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

Annotations already declare readOnly, idempotent, non-destructive, and open-world behavior, so the bar is lower. The description adds genuinely new context: that it lists URLs without fetching content and that each call costs 1 credit, which matters for budgeting. It does not mention result limits or pagination behavior for large sites.

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?

Two tight sentences with no waste. The core behavior leads, followed by the routing guidance, and the credit cost is a brief trailing note.

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 single-parameter, read-only discovery tool with no output schema, the description covers what it does, when to use it, and its cost. It could say more about the shape or volume of the returned URL list, but nothing essential to correct invocation is missing.

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 coverage is 100% and the single url parameter is fully documented in the schema including the https:// requirement, so parameter meaning is already handled. The description adds nothing further about the parameter; baseline 3 is appropriate.

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?

States a specific verb (list) and resource (URLs found on a website) plus the key scoping constraint that content is not fetched. This cleanly separates it from supadata_scrape (which reads content) and supadata_crawl (which traverses), both named in the description.

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?

Explicitly names two use cases and the alternatives that follow: discover pages before choosing which to read with supadata_scrape, or check site size before starting a supadata_crawl. The agent has a clear decision rule for selecting this tool over its siblings.

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