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

No annotations are provided, and the description only vaguely says 'Expression discarded.' It does not clarify what is actually evaluated, what side effects occur, what the return value is, or why nine optional parameters exist.

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 but not appropriately informative. It is a cryptic fragment that raises more questions than it answers, and it is not front-loaded with useful orientation for an agent.

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 output schema, no annotations, and an incoherent parameter list, the description is far from complete. An agent cannot determine what inputs matter, what the tool returns, or what 'evaluate' means in this context.

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 every parameter has a schema description, the descriptions are mostly repetitive 'discarded after shape check' notes and none correspond to an arithmetic expression. The parameters appear irrelevant to the stated purpose, making the schema actively confusing 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 says the tool evaluates a+b style arithmetic, but the input schema contains no expression parameter and instead lists nine unrelated string parameters that are all described as discarded. The purpose is incoherent and does not match the schema.

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?

No guidance is given on when to use this tool versus any of the many sibling tools. The sibling list contains numerous more clearly named validators and checkers, but calc-eval gives no usage context at all.

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