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

With no annotations, the description carries the full burden. It discloses determinism, fixture-verification, rate limits, api_key usage, and the exact repair steps. However, it claims 'Returns the result plus a Guild-signed provenance envelope,' yet the provided output schema (with additionalProperties: false) does not include such an envelope, creating a minor inconsistency.

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 relatively long but dense with useful information. It front-loads the main purpose and uses a clear flow: what it does, how to use, constraints, and return value. Including the full schemas adds length but is valuable; still, it could be tightened.

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 output schema is provided, the description still adds essential context: use case, repair behavior, rate limits, auth, and return contents. For a tool with moderate complexity, this is comprehensive and allows an agent to select and invoke 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 description coverage is 0%, but the description compensates by embedding the exact JSON Schema for `payload` and explaining `api_key` ('pass your Guild api_key to use your member budget'). This fully clarifies both parameters beyond what the outer input schema offers.

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 repairs malformed JSON into parseable JSON, with a specific verb ('repair') and resource ('malformed JSON'), and distinguishes it from sibling tools like json_validate and json_canonicalize by mentioning specifics like stripping code fences and fixing Python/JS literals.

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 explicitly says 'Use when a model or upstream tool emitted JSON that json.parse rejects,' giving clear usage context. It does not name alternative tools or state when not to use it, so it falls short of the highest bar.

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