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

The description goes beyond annotations by explaining key behavioral details: how arrays are handled (not by position, but by identity or order), how paths are formatted (dot notation, [id=42]), and that reordered elements are treated as a single change. This is significant added context beyond the readOnly/idempotent annotations.

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 two sentences long, directly to the point, and contains no filler or redundancy. It efficiently conveys the core purpose and a key behavior in a compact form.

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?

The description is quite complete given that an output schema exists. It explains the main return semantics (added, removed, changed keys) and the special handling of arrays, which covers the essential aspects. It does not need to detail return format since that is presumably in the output schema. A minor gap is not explaining depth limit behavior, but that is likely covered by the max_depth 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?

Schema coverage is 100% with descriptions for all three parameters, and the description does not add substantially new info about them beyond what the schema already states. The description's mention that values can be strings or JSON objects is already present in the schema types and descriptions, so it provides minimal added parameter insight.

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 tool's function: computing a deep structural diff between two JSON values. It uses a specific verb (compute) and a specific resource (JSON values), and distinguishes it from sibling tools like diff_text or diff_mappings by focusing on structural JSON comparison.

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 a concrete use case ('perfect for API response regression testing') which helps an agent decide when to employ this tool. However, it does not explicitly mention alternative tools or when not to use it, though the context is sufficiently implied.

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