Extract rendered text from a webpage to verify copy, hierarchy, and content loading. Use a CSS selector to scope the extraction or truncate output as needed.
Read the rendered text of the page, to check copy, hierarchy, and that content actually loaded.
| Name | Required | Description | Default |
|---|---|---|---|
| selector | No | CSS selector to scope to. | |
| max_chars | No | Truncate at this many characters. |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the burden of behavioral disclosure. It communicates that this is a read-only operation and that it returns rendered text, which is useful. However, it does not mention potential runtime caveats such as waiting for load, handling of empty selectors, or what happens if content has not loaded.
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, front-loaded sentence delivers the core action, the resource, and the use case with no filler. Every word earns its place.
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 simple read-only tool with only two optional, fully documented parameters, the description provides sufficient context for an agent to decide when to call it. It could be slightly richer about return value format or edge cases, but nothing essential 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?
Schema description coverage is 100%, so the schema already documents both selector and max_chars. The description adds no additional parameter-level semantics beyond the stated purpose, which is acceptable but not additive.
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 uses a specific verb ('Read') and resource ('rendered text of the page'), and gives the purpose ('check copy, hierarchy, and that content actually loaded'). This clearly distinguishes it from visual or console-oriented sibling tools like screenshot, read_console, and audit_design.
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 states concrete use cases: checking copy, hierarchy, and whether content loaded. It does not explicitly name alternatives or say when not to use it, but the stated purposes make the appropriate context clear enough.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.