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 helpfully discloses the exact computation (net income ÷ shares), which is real transparency for a pure function, but says nothing about output format, rounding/precision, or edge cases such as zero or negative share counts.

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?

Two compact sentences with the purpose and formula front-loaded and no filler. The closing 'Provide netIncome and shares' slightly restates the schema, but it is justified because the schema descriptions are uninformative.

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?

For a deterministic calculator with no output schema and no annotations, the definition covers inputs and the computation adequately. It is missing return-value expectations (format, decimal places) and the fact that both parameters are effectively required despite the schema declaring zero required 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?

Although schema coverage is 100%, the schema's own descriptions are tautological ('Shares to process', 'NetIncome to process'). The description supplies real domain meaning by defining netIncome as net income and shares as the share count in the division. It also implies both values are needed even though the schema marks nothing required.

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?

Names a specific verb+resource and goes further by spelling out the formula: 'Calculate Earnings Per Share: net income divided by number of shares.' An agent can distinguish EPS from the inverse earnings-yield sibling. It stops short of explicitly naming or contrasting with that sibling, so it is clear but not fully differentiated.

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 only guidance is 'Provide netIncome and shares,' which is an input instruction rather than a when-to-use statement. No conditions, prerequisites, or alternatives (e.g., earnings-yield, price-earnings) are mentioned. Usage is only implied by the tool name.

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