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

Discloses critical behavioral traits: data sources (PubChem GHS, CAMEO), pricing ($0.03 USDC via x402), and automatic client payment. No annotations exist, so the description carries full burden. Missing rate limits or error handling details, but still strong.

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?

Three sentences: opens with the core question, specifies inputs/outputs, ends with pricing. No wasted words, information-dense and well-structured.

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?

Covers all essential aspects for a chem-compatibility tool: purpose, inputs, outputs (verdict, reason, effects, confidence), data sources, and cost. No output schema exists, but the description explicitly lists return fields.

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?

Both parameters have schema descriptions (100% coverage). The description adds value by clarifying that inputs can be 'CAS numbers or names', reinforcing the schema. No enums or additional constraints needed.

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 opens with a clear, specific question: 'Can chemical A be safely mixed or stored with chemical B?' followed by inputs and outputs. It differentiates from sibling 'chem-safety' by focusing on compatibility rather than general safety.

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?

Explicitly states required inputs ('Pass two CAS numbers or names') and describes the JSON response structure. Lacks explicit when-not-to-use or alternatives, but the narrow scope makes usage straightforward.

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