words

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

No annotations are provided, so the description carries the burden. It discloses the default split behavior and RegEx requirements, but lacks edge-case details like handling of empty strings, what is returned, or behavior when delimiter is not found.

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?

Three sentences with front-loaded purpose, then specific formatting rules. No wasted words; each sentence adds necessary information.

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 simple split tool, the core usage is covered (delimiter, default, regex). However, there is no mention of return type, empty input behavior, or output schema, and the empty input schema undermines completeness by not formally declaring the delimiter parameter.

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 schema has zero properties, yet the description introduces a 'delimiter' parameter and explains its format (String or RegEx with slashes). This adds meaning beyond the schema, but the schema's emptiness creates an invocation gap: the agent cannot determine how to actually pass the delimiter. The description cannot fully compensate for the missing parameter definition.

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 states 'Split string by delimiter' with a clear verb and resource, and adds the default whitespace behavior. This distinguishes it from siblings like 'regex' or 'replaceall' which handle different operations.

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?

It explains the default behavior (whitespace) and provides specific RegEx formatting instructions, but does not explicitly say when to use this over alternatives like 'regex' or other string operations. Usage is implied but not directly contrasted with siblings.

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