chunker_chunk_by_separator

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

With no annotations, the description must disclose behavioral traits. It mentions optional merging up to max_chars, which is helpful but incomplete. It does not explain what happens if the separator is not found, how merging works, or other edge cases, leaving some ambiguity.

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 very concise, consisting of two short sentences that immediately state the core functionality. It is front-loaded with the main action, but could be slightly longer to cover missing parameter 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?

Given the tool has four parameters, no annotations, and a output schema, the description is too minimal. It does not explain the merging algorithm or the keep_separator parameter, which are essential for correct use. The output schema exists but its format is not hinted, though not required.

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 0% description coverage, so the description must compensate. It only explains the separator and max_chars parameters implicitly, but fails to mention the keep_separator parameter entirely. This leaves a key parameter undocumented.

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 that the tool splits text on a custom separator and optionally merges parts up to a maximum character count. This distinguishes it from other chunker tools like chunker_chunk_sliding_window or chunker_chunk_text, which use different splitting strategies.

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 does not provide any guidance on when to use this tool versus alternative chunker tools. It only states what it does, without mentioning when it is appropriate or when other tools would be better.

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