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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false, and destructiveHint=false. The description adds that results are finite and real, and that angle mode matters for trig, but does not explain error behavior for invalid or undefined expressions.

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 short sentences, purpose first, then angle choice and result type. No filler and appropriately front-loaded.

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 low-complexity evaluator with full schema descriptions, rich annotations, and an output schema, the description covers the core purpose and angle mode. It is largely complete, though it omits routing guidance against the many specific calculator siblings.

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 the angleUnit enum/default and expression token/nesting limits. The description repeats the angle choice and adds 'with parentheses,' which is marginal beyond the schema.

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?

States a specific verb (Evaluate) and enumerates the function families (arithmetic, powers, roots, logs, trigonometric) plus parentheses. This clearly distinguishes it from narrow siblings like average_calculator or percentage_calculator, though it does not explicitly contrast with logarithm or power.

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?

Gives no when-to-use context, no exclusions, and no alternatives among the many calculator siblings. The advice to choose degrees or radians is parameter setup, not usage routing.

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