as_json_patch

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

With no annotations supplied, the description carries real weight and does so well: it discloses that every patch is self-verified by applying it to a and re-diffing against b, that arrays use remove/add/move to preserve keyed item identity, that output is only equivalent up to ignore/tolerance options, and that NaN/Infinity are rejected. Remaining gaps are smaller — no mention of size limits, performance, or side effects (whether anything is written to disk) — which keeps it from a 5.

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 structure is front-loaded and logical: purpose first, then verification and array/edge-case semantics, then a compact args block. Nearly every sentence adds information, though the deferred 'as in diff_files' line is a low-value substitute for actual parameter meaning.

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?

An output schema exists, so return-format explanation is appropriately omitted, and the safety story is clear since the tool generates rather than applies a patch. However, for an 11-parameter tool with zero schema descriptions, leaving eight parameters to be looked up elsewhere means the definition is not fully self-contained.

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 0% across 11 parameters, so the description must compensate, and it only partly does. It clarifies a/b as file paths versus inline documents depending on inputs, and states that text mode requires an explicit format, but the remaining eight parameters (format, array_match, array_keys, ignore, abs_tol, rel_tol, strip_comments, encoding) are disposed of with 'as in diff_files' — a cross-reference that helps only if the agent has that sibling's documentation loaded.

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 first sentence names a specific verb and artifact: 'Generate an RFC 6902 JSON Patch that transforms document a into document b.' That is far more precise than a generic diff tool, but the description never explicitly contrasts itself with the listed siblings (diff_files, diff_text, apply_preview), leaving the agent to infer that this one emits a patch rather than a human-readable diff.

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?

Usage is only implied: 'inputs: files (default) or text; text requires an explicit format' tells the agent which mode to pick, and the ignore/tolerance caveat hints at when the result is approximate. There is no explicit statement of when to call as_json_patch instead of diff_files or apply_preview, and no stated prerequisites or failure conditions beyond NaN/Infinity rejection.

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