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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered by structured data. The description adds only the mathematical operation and an example, without disclosing additional behavioral context such as handling of negative numbers or floating-point behavior. This is acceptable given annotations but adds little beyond them.

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 a single sentence plus a compact example, with the core operation front-loaded. Every element earns its place and nothing is wasted.

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-value documentation is not needed. The description fully covers the operation for a simple two-parameter modulo tool. It could be slightly richer by noting edge cases (e.g., negative operands) or linking to sibling tools, but it is sufficient for correct 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 description coverage is 100%, and the schema already documents dividend and divisor with examples and constraints (divisor must be non-zero). The description restates the parameter roles in plain language ('dividend mod divisor') but adds no syntax, format, or edge-case details beyond the schema. Baseline 3 is appropriate when the schema does the heavy lifting.

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: 'calculate the remainder: dividend mod divisor', and includes a concrete example. It is clear what the tool does, though it does not explicitly differentiate itself from related siblings like calculator_gcd or calculator_divmod (if any), which keeps it just below a 5.

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 phrase 'Use this to calculate the remainder' implies the usage context, but there is no explicit guidance on when to choose this tool over alternatives (e.g., calculator_gcd, calculator_lcm, or general arithmetic tools) or any exclusions. The example clarifies the operation but does not add decision criteria.

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