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

With no annotations, the description carries the full burden of behavioral disclosure. It only says the expression is discarded, but does not state what is returned, whether inputs are stored, whether side effects occur, or what happens for unsupported inputs. The schema's many 'discarded after check' notes are not reflected in the description and further obscure behavior.

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 text is very short and front-loaded, with no filler or repeated schema content. However, the brevity is under-specification rather than effective conciseness, because the description lacks the information needed to align the purpose with the nine-parameter schema.

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?

This is a nine-parameter tool with no output schema and no annotations, so the description must explain what the tool does with inputs, what it returns, and when to use it. The two sentences cover none of that and even omit the required arithmetic operand. An agent cannot correctly invoke this tool based on the definition.

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%, yet none of the nine parameters corresponds to the advertised arithmetic expression. The description adds no mapping from 'a+b' to any field, and several schema descriptions ('search text', 'JSON text', 'file path') point to unrelated operations. This provides more confusion than value beyond the raw 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?

The description names a concrete operation ('Evaluate a+b style arithmetic'), but 'Expression discarded' muddles whether the tool returns a result or simply ignores input. The schema provides no expression parameter, so the stated purpose cannot be mapped to any field. It also does not meaningfully differentiate from the many sibling check/hint tools.

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 when-to-use guidance, prerequisites, or exclusions are provided. There is no mention of alternatives or cases where a sibling tool such as validate-json, search-query-len, or normalize-url should be chosen instead. Use must be inferred entirely from the name and single verb.

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