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

Beyond idempotentHint=true and readOnlyHint=false, the description reveals pricing (300 micro-dollar credits per successful call), credential prerequisites, the mandatory prepare step, and the critical nuance that only reused requestId arguments enable recovery without a new charge. This is exactly the operational context an agent needs for a paid, stateful tool.

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?

Every sentence earns its place: purpose, JCS caveat, pricing, prerequisites, and recovery behavior are all packed into four tight sentences. The functionality statement is front-loaded, followed by operational warnings in logical order. There is no repetition or filler, and the key cost warning is clearly highlighted.

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 paid tool with an output schema and a multi-step preparation requirement, the description covers the essential operational lifecycle: prepare, authorize, call, recover, and avoid duplicate billing. Combined with the output schema and input parameter descriptions, an agent has enough context to invoke the tool correctly and manage its cost implications.

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 already describes requestId and maxPriceMicroUsd, covering 67% of parameters. The description adds important billing semantics around requestId: reusing prepared arguments is recovery, while a new requestId is a new billable operation. It does not elaborate on the open 'data' property, but the tool name and purpose make its role sufficiently clear.

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 uses a specific verb and resource: 'Serialize JSON with sorted object keys for deterministic comparison.' It also explicitly disclaims RFC 8785 certification, which prevents an agent from assuming strict JCS compliance and differentiates this tool from related JSON utilities like data_json_diff and data_json_patch.

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 clear procedural guidance: run agent_utilities_prepare first, require existing credits and a private Authorization header, and reuse prepared arguments for recovery. It also warns that a new requestId creates a new billable operation. It stops short of explicitly naming sibling alternatives or stating when to prefer canonicalization over diff/patch, which would have made this a 5.

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