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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered elsewhere. The description contributes nothing additional — no statement of what is computed, what happens with partial inputs, or what is returned, which is what would earn credit here.

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?

It is only two words, so there is no waste, but this is under-specification rather than conciseness. Nothing is front-loaded because there is nothing substantive to front-load.

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 tool with three interdependent numeric parameters, no output schema, and zero schema documentation, the description must carry the interpretive burden and carries none of it. An agent could not reliably call this tool correctly from the provided information.

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 0% for three numeric parameters, and the description supplies no meaning at all. Critically, it never explains the relationship between originalPrice, salePrice, and discountPercent — an agent has no way to know whether to supply two of them to derive the third, or whether discountPercent overrides salePrice.

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?

"Discount calculator" restates the tool name almost verbatim and adds no verb or scope beyond what the name already conveys. An agent cannot tell from this text how it differs from the dozens of sibling calculate_* tools other than by the word "discount".

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 when-to-use guidance, no prerequisites, and no reference to alternatives — even though the sibling list contains closely related tools like calculate_sales_tax, percentage, and calculate_tip that an agent must choose between. The intended usage is only implied by the tool name.

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