browser_fetch

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

Annotations already indicate read-only, idempotent, and non-destructive behavior. The description adds useful context: it uses a real browser (Playwright) and converts to markdown, which is beyond what annotations provide. It does not mention edge cases like CAPTCHA handling, but the schema covers that via the 'headed' parameter.

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, front-loaded sentence that conveys the essential purpose without unnecessary words. It earns its place and is easily scanned.

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's moderate complexity (8 params, output schema present), the description is sufficient: it names the core function and output. It does not need to explain return format since the output schema exists. Slightly more context about when to prefer this over smart_fetch could improve it, but it's already fairly complete.

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%, so the baseline is 3. The description does not add meaning beyond the schema; all parameter details are already in the input schema. It adds no new semantic information to justify a higher score.

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 fetches JavaScript-rendered pages using Playwright and returns markdown, with a specific verb ('fetch'), resource ('page'), and output format. This distinguishes it from sibling tools like pdf_fetch (PDFs) and web_search (search results).

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 implies this tool is for pages that require JavaScript rendering, giving clear context on when to use it. However, it does not explicitly mention alternatives or exclusion criteria, so it stops short of a 5.

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