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

Goes well beyond the annotations (readOnlyHint=false, destructiveHint=true, openWorldHint=true, idempotentHint=false) by quantifying exact credit costs per proxy tier, warning that target 404s can still be billed, declaring no automatic retry, and flagging returned content as untrusted. This is exactly the cost/consent surface an agent needs before invoking a billable write-like call.

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?

Front-loads 'BILLABLE READ:' as the gating signal, then packs cost, consent, retry, and trust caveats into a few dense clauses with no filler. Every clause changes agent behavior.

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 billable 4-param tool with no output schema, it covers cost, consent gating, retry semantics, and data trust. It is only slightly thin on what the response actually contains (raw HTML body? status code? headers?) and on failure/error behavior beyond 404 billing.

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%, so all four parameters are already documented, and the description's mention of standard vs premium proxy credits and the confirm requirement largely restates the schema. Baseline 3 applies since the schema carries the parameter burden.

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?

Specific verb+resource ('Fetch one public page as HTML') with an explicit scope qualifier ('without JavaScript') that implicitly routes JS-dependent work to the render_page sibling. It stops short of naming the sibling, so the differentiation requires a small inference.

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 supplies decision-relevant conditions — billable, 'Requires confirm:true', 'Never retries automatically' — but never states when to use scrapeowl_render_page or scrapeowl_extract_elements instead. The no-JS qualifier hints at the boundary without making it explicit.

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