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

Annotations already indicate read-only and idempotent behavior; the description adds that output is a percentage and defines the financial relationship, which is useful beyond the schema. No contradiction with annotations.

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?

A single, tight definition followed by a units note. No wasted words; the core concept is front-loaded and 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?

For a simple two-input formula with full schema coverage, annotations, and an output schema, the description is sufficient. It could mention the inverse relationship to after-tax-yield, but that is not essential for selection and invocation.

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 coverage is 100%: both parameters have clear descriptions ('Marginal tax rate in percent' and 'Tax-free yield in percent'). The description only restates the percent convention without adding deeper parameter relationship details.

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 gives a specific definition: computes the taxable yield that matches a tax-free yield (e.g., municipal), distinguishing it from inverse tools like after-tax-yield. It also clarifies units with 'Percents in and out,' making the purpose unmistakable.

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?

Clear context is provided: use when you have a tax-free yield and want its taxable equivalent. It does not explicit name alternatives or when-not conditions, but the scenario is obvious and implied.

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