Retrieve the HTML source of a full page or a specific element using a browser session ID. Use it to extract or inspect rendered webpage content after navigation.
Get the HTML source of an element or the full page.
| Name | Required | Description | Default |
|---|---|---|---|
| selector | No | CSS selector of the element (omit for full page HTML) | |
| session_id | Yes | Session ID returned by browser_navigate |
Changes observed during successful MCP inspections.
v2.7.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds nothing beyond the factual operation: no note on invalid-selector errors, on result size for full-page HTML, or on what happens if the element isn't present.
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 with no filler; the scope contrast (element vs full page) is stated immediately. It is slightly redundant with the schema's selector description but wastes no space.
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 two-parameter read-only tool with a fully described schema, the description is minimally sufficient, and no output schema exists so return values need not be explained. It nonetheless omits practical caveats (large payloads, invalid selectors) that an agent would benefit from.
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 coverage is 100%, with the selector description already stating 'omit for full page HTML'. The description's 'element or the full page' phrasing mirrors the schema without adding format or syntax detail, so the baseline 3 applies.
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?
States a specific verb ('Get') and resource ('HTML source'), and clarifies the two scopes (element vs full page). It distinguishes itself from browser_get_text and browser_get_attribute implicitly, though it never names those siblings explicitly.
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 when-to-use or when-not-to-use guidance, and no routing to alternatives such as browser_get_text for visible text or browser_get_attribute for a single attribute. The agent gets no help choosing among the many sibling getters.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.