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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds concrete behavioral context: it fetches via ScrapeUnblocker API, returns a specific JSON structure {url, count, elements:[...]} with ready-to-use selectors, and that it replaces raw HTML. It doesn't cover error cases or rate limits, but the safety profile is already annotated, so a high score is warranted.

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 wasted words. The purpose is front-loaded, followed by the output format and usage guidance. Every clause contributes to the agent's decision-making.

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?

No output schema exists, so the description compensates by specifying the return JSON shape ({url, count, elements:[...]}) and that selectors are ready-to-use. It covers the essential workflow (discover then drive). Minor omissions like pagination or error behavior are acceptable for a read-only inspection tool.

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 description coverage is 100%, so the schema fully documents all 5 parameters. The description does not add parameter-level detail beyond the schema, but it does mention the `steps` param of fetch_html as a follow-up, which is tangential. Baseline 3 is appropriate given the schema's thoroughness.

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 states a specific verb ('Fetch a page... return its interactive elements') and resource (ScrapeUnblocker API). It explicitly contrasts with raw HTML and names the sibling fetch_html, making it clear this tool is for element discovery rather than general page fetching.

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?

Provides explicit usage direction: 'Use it to discover what to target, then drive the page with the `steps` param of fetch_html.' This tells the agent when to use this tool and points to the alternative for subsequent actions, leaving no ambiguity.

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