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

No annotations are provided, so the description must carry the full behavioral burden. It discloses only that the expression is discarded, implying a stateless operation, but says nothing about side effects, return behavior, failure modes, or whether any input is persisted.

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 short and front-loaded, but the second sentence, 'Expression discarded,' is cryptic and does not clearly earn its place. The terseness comes at the cost of essential information.

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?

With no annotations, no output schema, nine parameters, and no explanation of what result is produced or which parameter holds the expression, the description is not complete enough for safe invocation. The schema richness does not compensate for the missing connection between the stated purpose and the actual inputs.

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 the schema descriptions are comprehensive, the description references an 'expression' that does not map to any of the nine schema properties. With additionalProperties set to false, an agent following the description cannot determine where to place the arithmetic expression, making the description actively misleading rather than helpful.

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: 'Evaluate a+b style arithmetic.' This is clear enough to distinguish the tool's topic from the many validation and hint siblings, though it never says what the evaluation returns and does not explicitly differentiate from alternatives.

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?

There is no guidance on when to use this tool versus any sibling, no use-case context, no prerequisites, and no exclusions. An agent is left to guess when 'calc-eval' is appropriate.

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