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 safe, closed-world, pure-compute profile is covered without description help. The description adds the input→output shape via its example, but says nothing about error behavior for malformed or non-linear input.

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?

One sentence, front-loaded with the verb and scope, with the example doing real work rather than padding. Nothing extraneous.

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 an output schema present and annotations covering safety, the description needs only to pin down input form and scope, which it does. The one gap is the optional 'variable' parameter's behavior when absent, which is left unaddressed.

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%, so both parameters are already documented and the baseline is 3. The example reinforces the expected 'equation' format (must contain one '='), but it doesn't clarify the 'variable' parameter's role or what happens when it is omitted.

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?

Specific verb ('Solve') plus resource ('a linear equation in one unknown'), with a worked example that removes ambiguity about degree and number of unknowns. It separates the tool from quadratic/system solvers implicitly, but never names those siblings explicitly.

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 'linear equation in one unknown' implies where this fits relative to calculator_quadratic_equation, calculator_system_of_equations, and calculator_numerical_solve, but no alternative or exclusion is stated. An agent must infer the boundary from the wording alone.

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