arno.apply

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

The description discloses key behaviors beyond the destructiveHint annotation: atomicity ('all land or none do'), validation of anchors before writing, formatting of touched files, and a single validation at the end. These are not covered by the annotation and give the agent a solid understanding of the tool's execution model.

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 three concise sentences with no fluff. The core atomic behavior is front-loaded, followed by the ops list and key behavioral details. Every sentence 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?

For a complex tool with multiple edit types, the description covers the atomicity guarantee, ops, validation, formatting, and usage guidance. With full schema coverage and a single annotation, nothing essential is missing for an agent to correctly invoke and reason about the tool.

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%, so all parameters are already documented in the schema. The description does not add parameter-specific meaning beyond what the schema provides, but it does clarify the overall operation context. Baseline 3 is appropriate given the high coverage.

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 a specific verb ('Apply') and resource (several edits as one atomic unit), lists the supported ops, and explicitly differentiates from sibling single-edit tools by noting it should be preferred when changing more than one site. An agent can clearly understand what this tool does and how it differs from alternatives.

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 gives explicit usage guidance: 'Prefer this over several single edits when changing more than one site.' This tells the agent when to use this tool versus the single-edit siblings, and the atomicity requirement implies when it's necessary. Clear and actionable.

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