extract_embedded_state

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

The description adds meaningful behavioral context beyond annotations: 'One fetch, exact values, no LLM in the extraction path, so nothing can be fabricated,' and warns payloads are often over a megabyte. It also discloses the credit cost, which is useful operational behavior. No contradiction with the readOnly/idempotent/destructive annotations.

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?

Every sentence earns its place: purpose, framework guidance, behavioral guarantee, payload-size warning, non-usage exclusion, cost, and a realistic example. It is dense but well organized, front-loading the core decision before the details.

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?

Despite having no output schema, the description gives enough to invoke the tool correctly: when to use it, how to scope large results with path, an executable example, and clear non-targets. The schema covers parameter mechanics like robots and inline limits, so no critical guidance 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?

Input schema coverage is 100%, so the baseline is 3. The description adds value by explaining why path matters ('Payloads are routinely over a megabyte') and giving a concrete path example ('next_data.props.pageProps'), going beyond the schema's syntax note.

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 names a specific verb and resource: extracting data from a page's embedded JavaScript state rather than rendered HTML. It explicitly identifies frameworks (Next.js, Nuxt, Apollo, Redux, application/json blocks) and distinguishes itself from scrape with 'Not for the rendered text of a page (scrape) or for sites built without a framework payload.'

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 opening line states the exact condition for use: 'Use this when a page's data lives in its embedded JavaScript state rather than its rendered HTML.' It also gives an explicit exclusion and the name of the alternative (scrape), plus an example showing the intended call shape.

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