Get rendered page HTML

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

Annotations already assert readOnly=true and destructiveHint=false. The description adds the valuable behavioral detail that only server-rendered HTML is returned (JS-injected content absent), which goes beyond annotation coverage. No contradiction.

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 with zero fluff, front-loaded with the purpose and motivation. The caveat and optional modes are packed efficiently, though there is a slight repetition of 'HTML' but not a problem.

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?

Adequate for a read-only fetch tool: purpose, output type, and the crucial JS limitation are covered. Parameters like max_chars, site_id, and preview_token are documented in schema, so no critical gap for an agent to invoke correctly.

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 covers all 5 parameters with descriptions, so baseline is 3. The tool description adds a high-level summary of extraction modes but no new syntax or mechanics beyond what the schema already provides.

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 specific verb 'Fetch' and resource 'fully rendered HTML for any URL on the site', with a clear motivation to verify front-end changes. It contrasts with 'trusting the API's word', which distinguishes it from content APIs without naming them.

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 clear context on when to use (verifying changes on the front end) and a key caveat about JavaScript-injected content. Does not explicitly name alternative tools or when-not situations, but the guidance is sufficient for a read-only fetch.

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