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

With no annotations provided, the description carries the full burden of behavioral disclosure. It discloses deterministic behavior, lists specific repair actions, and states the payment cost ($0.005 USDC on Base via x402). It does not mention error handling for unrepairable input or the exact return format, which are minor gaps for a simple single-parameter 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?

The description is two sentences with no wasted words. The first sentence front-loads the core purpose and behaviors, the second sentence states the cost. Every element 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?

Given the simple complexity (one parameter, no output schema), the description is largely complete. It provides the tool's purpose, specific fixes, and cost. The only missing element is an explicit statement of the return value (e.g., repaired JSON string), but for a utility like this, the return is inferable.

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 100% of the parameter (text), providing a baseline of 3. The description adds semantic value by explaining what 'malformed JSON' means (LLM output with code fences, trailing commas, single quotes, unquoted keys), which helps agents understand the expected input format more deeply than the schema alone.

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 with a specific verb ('repair') and resource ('malformed JSON from LLM output'), and enumerates concrete behaviors (strip code fences, fix trailing commas/single quotes/unquoted keys, balance braces). This distinguishes it from the unrelated sibling tools (crypto market, DNS, URLs).

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 implies when to use the tool: when dealing with malformed JSON from LLM output. It provides context and specific examples of malformations. However, it does not explicitly state when not to use it, nor does it mention alternatives. Since no sibling tool handles JSON repair, the lack of explicit alternatives is acceptable.

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