Extract Structured Data

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

With no annotations provided, the description must fully disclose behavior. It mentions 'Gemini JSON mode' and that it 'returns parsed JSON', but does not discuss error handling, file size limits, or permissions needed. The phrase 'almost any local file' is vague. There is no annotation contradiction.

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 only two sentences, with the purpose and method in the first sentence and key parameters in the second. It is front-loaded and waste-free. However, it could be slightly more structured by separating the input types from the output.

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 tool's complexity (6 parameters, wide input types) and the presence of an output schema (though not provided), the description covers the core functionality well: what it does, how to specify fields, and how to constrain output. It is complete enough for most use cases, though it does not detail the exact return format (referencing 'parsed JSON' is sufficient given output schema).

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?

All 6 parameters have descriptions in the input schema (100% coverage), so the description adds minimal extra meaning. It clarifies the purpose of 'instructions' and mentions that 'json_schema' can constrain output, but these points are already implied by the schema descriptions. Baseline 3 is appropriate.

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 it extracts structured JSON from text or local files using Gemini JSON mode. It is specific about the verb 'extract' and the resource 'structured JSON', but does not explicitly differentiate from sibling tools like 'analyze_image' or 'ocr', which could also extract data from files. However, the scope is broad, and the description is unambiguous.

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 suggests using the tool when you need structured data from various file types, but it does not provide when-not-to-use or alternatives among siblings. The mention of 'optional' json_schema gives some guidance, but there is no explicit usage context or exclusion criteria.

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