web_extract

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

With no annotations provided, the description carries the full burden of behavioral disclosure, but it only states the core action. It doesn't describe behavior for selectors that match nothing, whether the page must be pre-fetched/cached, rate limits, or error handling. For a network tool this is a notable gap.

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?

A single efficient sentence with zero filler, front-loading the core purpose and mechanism. It earns its length, though it could have used its brevity to add a critical detail about the rules format.

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?

The output schema covers the return format, but the tool has two required parameters, one of which (rules) has an unspecified format, no usage guidance relative to siblings, and no behavioral expectations. For a 2-param tool this is thin — the agent lacks enough to invoke it correctly on the first try.

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 0%, so the description must compensate. It tells us the tool uses CSS selectors (hinting at the rules parameter) and that url is the target page, but it doesn't specify the rules string format — is it a JSON mapping of field names to selectors, a list, or a single selector? This ambiguity puts the burden on the agent to guess.

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 (extract) + resource (web page) + mechanism (CSS selectors), and the phrase 'structured data' signals it differs from simply fetching raw content. This conceptually distinguishes it from siblings like web_fetch and web_crawl, which an agent could infer even without explicit sibling comparison.

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?

No guidance on when to use web_extract versus web_fetch or web_search. The description doesn't state when extraction is preferable to a raw fetch, whether extraction works on JS-rendered pages, or any conditions under which a sibling should be chosen instead.

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