query_selector

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

With no annotations, the description carries the full burden of behavioral disclosure. It mentions 'structured match previews' but does not reveal truncation behavior (html_chars, text_chars, limit), size limits, or how document_handle/source_url/html are prioritized. These are significant behavioral traits not disclosed.

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?

The description is a single concise sentence with no unnecessary words. However, it omits critical details, so while concise, it sacrifices informativeness. It is not bloated, but it is under-specified for the tool's complexity.

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?

Given the tool has 11 parameters and an output schema, the description is highly incomplete. It does not explain the relationship between input sources (html, source_url, document_handle), the meaning of preview limits, or how to choose between CSS and XPath modes. The output schema exists but the input semantics are entirely undocumented.

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%; the description adds no meaning beyond the raw schema. Even the mention of 'CSS or XPath' weakly maps to the mode parameter, but none of the 11 parameters are explained, leaving the agent to guess semantics for html, document_handle, truncate_on_limit, max_size_bytes, etc.

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 clearly states the tool's function: running a CSS or XPath query with scraper_rs and returning structured match previews. It specifies the verb, resource, and output type, and distinguishes it from CDP-related siblings like query_selector_cdp by noting the scraper_rs implementation.

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 is provided on when to use this tool versus alternatives such as query_selector_cdp, compare_selectors, or analyze_css_selectors. The description does not mention use cases, exclusions, or prerequisites.

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