json_diff

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

With no annotations provided, the description carries the full burden. It discloses the core behavior (showing added/removed/changed keys) but does not specify the output format, order of results, or error handling for invalid JSON. This adds some transparency but lacks comprehensive behavioral detail.

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 concise with two sentences: one for purpose and one for use cases. However, the leading '[PRO — 3 trial uses left]' is extraneous clutter that slightly detracts from the focus on tool functionality.

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 simple tool with two string parameters and no output schema, the description is fairly complete. It covers purpose, use cases, and output categories. It could mention the exact output format, but given the simplicity, it is adequate.

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 covers both parameters fully with simple descriptions ('First JSON string', 'Second JSON string'). The description reinforces that these strings represent JSON objects to be compared, but adds little beyond what the schema already conveys, such as validation requirements or parsing behavior.

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: 'Compare two JSON objects and show the differences — added, removed, and changed keys.' This is a specific verb+resource with distinct scope, and it differentiates from siblings like generic 'diff' or 'json_format' by focusing on the categorization of differences.

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 clear context for when to use the tool: 'Useful for debugging API responses, config changes, and state diffs.' This gives concrete use cases but does not explicitly mention alternatives or when not to use it.

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