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

No annotations are provided, so the description carries the full behavioral burden. It says 'Return,' which weakly implies a read-only computation, but it never states that the operation is non-destructive, deterministic, or free of side effects, nor does it mention authentication needs such as the api_key parameter. With zero annotation coverage, this is a significant disclosure gap.

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 tight sentences with zero waste. The core purpose is front-loaded, followed immediately by the usage context. Every sentence 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?

An output schema exists, so return values need not be described. The tool is simple and the purpose/usage are clear, making the description minimally viable. However, the complete absence of parameter explanation (especially api_key) and behavioral disclosure leaves meaningful gaps for an agent invoking the tool 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%, so the description must compensate for undocumented parameters. It implies the input is a SMILES string, but never explicitly says so, and it says nothing about the api_key parameter, leaving its purpose and usage completely unexplained. This adds minimal meaning beyond the bare parameter names and types.

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: 'Return the RDKit canonical SMILES.' It is clearly not a tautology and is distinguishable from most siblings by naming the exact chemistry operation. However, it does not explicitly differentiate itself from related siblings like covabasic_standardize or covabasic_convert, leaving that inference to the agent.

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 second sentence provides a clear intended context: 'Useful to normalize SMILES before comparison or database lookup.' This tells the agent when the tool is valuable. It does not name alternatives or exclusions, so it falls short of a full when/when-not/alternative routing guide.

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