insert_horizontal_rule

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

No annotations are provided, so the description carries full burden. It mentions the tool 'inserts' a horizontal rule, implying a write/mutation operation, but does not disclose behavioral traits like required permissions, whether it modifies document structure, error conditions (e.g., invalid index), or rate limits. This leaves gaps in understanding the tool's behavior beyond basic functionality.

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 front-loaded with the core action in the first sentence and uses a second sentence to provide useful context without redundancy. Both sentences earn their place by clarifying purpose and usage, making it efficiently structured and appropriately sized for the tool's complexity.

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 an output schema (implied by context signals), the description does not need to explain return values. It covers the basic purpose and usage context adequately for a simple insertion tool. However, with no annotations and mutation behavior, it could benefit from more detail on permissions or errors to be fully complete, though it meets minimum requirements.

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 description coverage is 100%, with clear descriptions for both parameters (document_id and index). The description adds minimal value beyond the schema by specifying the index is for insertion but does not provide additional context like valid index ranges or interaction effects. Baseline score of 3 is appropriate as the schema adequately covers parameter semantics.

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 specific action ('insert a horizontal rule'), identifies the resource ('at the specified index'), and distinguishes it from siblings by focusing on a unique formatting element (divider line) not covered by other tools like insert_text or apply_paragraph_style.

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 provides implied usage context by stating horizontal rules are 'useful for visually separating sections of content,' which suggests when to use it. However, it does not explicitly mention when not to use it or name alternative tools for similar purposes, such as insert_section_break or apply_paragraph_style for other separation methods.

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