batch_batch_filter

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

With no annotations, the description carries the full burden of disclosing behavior. It states the condition (fn(item) is truthy) and return format ({results, total, kept, rejected}). However, it does not clarify what 'fn' represents (e.g., a string expression or function name) or any side effects. Basic transparency is present but could be improved.

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 sentence plus a return format note. Every word is purposeful; no filler or redundancy. For a simple filtering operation, this is appropriately concise.

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 moderate complexity (2 required params, no enums, no nested objects) and no annotations, the description covers the core purpose and output shape. However, it lacks details about the fn parameter's syntax and potential error conditions. An agent might not know how to construct valid fn strings without external knowledge.

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 0%, so the description must compensate. It explains the 'fn' parameter's role in the filter condition ('fn(item) is truthy') and outlines the return structure, adding meaning beyond the bare schema. However, it does not specify the type or format of 'items' or 'fn' (e.g., that fn is a string evaluable expression).

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's function: 'Keep items where fn(item) is truthy'. The verb 'Keep' appropriately indicates filtering, and the resource is the items array. It distinguishes from sibling batch tools like batch_batch_map (which transforms each item) and batch_batch_partition (which splits based on condition).

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 explicit guidance on when to use this tool versus alternatives. The description implies filtering is the purpose, but does not mention when not to use it (e.g., when you need to transform items instead). Siblings like batch_batch_map and map_reduce_mr_filter exist, but no comparison is provided.

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