is_even

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

No annotations are provided, so the description carries the full burden. It describes the tool's behavior (checking divisibility by 2) but does not disclose additional traits like error handling, input constraints beyond integer type, or output format. It adds basic context but lacks depth for a tool with no annotation coverage.

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, efficient sentence with zero waste. It front-loads the core purpose and includes helpful domain/category tags without unnecessary elaboration. Every word 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?

Given the tool's low complexity (single integer input, simple boolean output), no annotations, and no output schema, the description is adequate but minimal. It covers the basic purpose and parameter semantics but lacks details on behavior, error cases, or return values, leaving some gaps for an agent to infer.

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 1 parameter with 0% description coverage. The description adds meaning by specifying the parameter's purpose ('a number') and the divisibility condition ('divisible by 2'), which compensates well for the schema's lack of documentation. However, it does not detail constraints like negative numbers or zero.

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 explicitly states the tool's purpose: 'Check if a number is even (divisible by 2).' It uses a specific verb ('Check') and resource ('a number'), and distinguishes from sibling tools like 'is_odd' by focusing on evenness. The domain/category tags add further context.

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 usage for arithmetic/number theory contexts, but does not explicitly state when to use this tool versus alternatives like 'is_odd' or 'is_divisible'. However, the purpose is clear enough to infer appropriate contexts, so it provides clear context without exclusions.

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