fetch_pages

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explains the return structure (results array, errors array), lists fields like blocked/status_code, and mentions js_render behavior. This gives substantial insight into what happens, though it omits rate limits or maximum URL count.

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 concise sentences deliver all necessary information: what it does, return format, error handling, and a config tip. Front-loaded and free of filler, every sentence 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 tool with 2 parameters and an output schema, this description is largely complete. It covers return structure, error handling, and a key behavioral switch (js_render). Missing rate limits or concurrency details, but these are not essential for basic use and could be inferred.

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%, so the description must compensate. It adds meaning for 'js_render' ('for JavaScript-heavy pages') and implies 'urls' are web page URLs via 'Fetch many web pages.' The explanation of js_render is a clear contribution beyond the schema, and the urls parameter is self-explanatory for this tool.

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?

Clearly states the verb+resource: 'Fetch many web pages in parallel.' Distinguishes from sibling tools like 'fetch_page' (singular) and 'crawl_site' (crawling) by emphasizing parallel bulk fetching. The return format and key parameters are explicitly mentioned.

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 a clear usage condition: 'Set js_render=true for JavaScript-heavy pages.' Implicitly communicates this is for fetching multiple pages at once (as opposed to 'fetch_page'), though it does not explicitly name alternatives or exclusions. Context is strong enough for correct selection in most scenarios.

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