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

Annotations already declare readOnly/openWorld/non-destructive, and the description adds meaningful context beyond them: per-call cost charged in USDC on Base or Solana from the key's SingIt limits, and the required 'search' scope. The 8000-character truncation limit also tells the agent to expect partial content on long pages.

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 sentences, no filler: the first gives the payload and size bound, the second gives the usage trigger. Cost and auth constraints are packed into one clause rather than a paragraph.

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 tool with no output schema, the description covers the return type, size limit, cost model, and required auth scope — everything an agent needs to decide and invoke correctly. Nothing material 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 there is only one parameter ('url', documented as 'The http(s) page to read'), so the schema carries the semantics. The description adds no format hints beyond that. 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 and resource ('The readable text of one web page'), adds the return-size cap (8000 characters) and the backend provider (Exa). The opening sentence makes clear this is single-page extraction, distinct from the search siblings in the list.

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?

'Use after web_search, or when you already have a URL' gives both entry conditions and implicitly routes the agent away from this tool when it has no URL yet. It doesn't state explicit exclusions (e.g., what to do when a page is JS-heavy or blocked), but the routing context is clear.

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