filter

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

With no annotations, the description carries the behavioral burden. It discloses a limitation (no nested Arrays) and explains how propertyName works for simple vs object arrays, but it does not mention return behavior, side effects, or condition syntax.

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, front-loaded with the core purpose, and every sentence adds useful information. No filler or redundancy.

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 filter operation with no output schema or annotations, the description covers the primary data-type cases but omits explicit return values, condition expression syntax, and edge-case behavior. It is adequate for simple use but incomplete for full autonomous invocation.

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?

The input schema has zero declared parameters, so the baseline is 4, but the description references a propertyName parameter that is not in the schema. It explains its use for different data types but never specifies how the 'condition' itself is provided, leaving a significant gap.

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 filters an Array based on a condition, which is a specific verb-resource pairing that distinguishes it from siblings like reverse, sort, or groupby. The nested-array exception adds scope detail, though it doesn't explicitly name alternative tools.

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 guidance is provided on when to choose filter over similar tools such as findfirst, any, or every. The instructions about using 'this' versus propertyName are parameter-level usage details, not tool-selection criteria.

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