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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so the safety profile is covered. The description adds genuinely new behavior: it 'repairs the JSON first if needed,' so malformed input is tolerated, and it discloses the compact output shape that lets the agent reason about token cost. It does not say what happens if repair fails or how the outline is formatted, which keeps it below 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 trigger condition is front-loaded, the output contract follows, and the next-step pointer closes it, all in roughly two sentences. The trailing 'Up to 100,000 characters' restates the schema's maxLength and is the one sentence that does not fully earn 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?

There is no output schema, so the description must describe the return value, and it does: keys, types, array lengths, and one example per repeated shape. Combined with the repair behavior and the named follow-up tool, an agent has everything needed to call it correctly.

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 max_depth, max_items and text all documented inline, so the schema carries parameter meaning. The description adds only the input ceiling ('Up to 100,000 characters'), which duplicates the schema's maxLength constraint rather than explaining how max_depth or max_items affect the outline.

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 states a specific verb and resource: it 'returns a compact outline of the structure (keys, types, array lengths, one example per repeated shape).' That output contract distinguishes it from the sibling mend_query_json, which pulls values rather than summarizing shape.

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?

It gives an explicit trigger ('when you are about to read a big JSON response, log or export into context, before loading it') and an explicit follow-up ('Follow with mend_query_json to pull only the values you need'). The two-step workflow and the alternative are both named, leaving nothing to inference.

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