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

Annotations already declare readOnly, idempotent, non-destructive and closed-world behavior, so safety is covered. The description adds the dual-mode behavior, but says nothing about what happens if both price and target_margin_percent are supplied, or about rounding/precision of results.

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?

A single compact sentence with no wasted words, and the primary mode is front-loaded before the alternate mode. The semicolon construction is slightly dense but still readable.

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 simple pure-function calculator with 100% schema coverage, full annotations and no output schema, the description tells the agent both what it computes and the alternate mode. Only the conflict case (both price and target margin supplied) 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%, including the note 'Give this or target_margin_percent', so the schema already carries parameter meaning. The description restates the same price-vs-target-margin choice without adding syntax, precedence rules, or edge-case behavior.

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 specific computational resource (profit, margin, markup) and states both input modes: cost+price, or cost+target_margin_percent. An agent can distinguish it from roi_calculator or percentage_calculator by the margin/markup framing, though no sibling is named 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 two modes imply when to use it (compute metrics from a known price, or derive a price from a target margin), but there is no explicit when-to-use / when-not-to-use guidance and no routing to alternatives such as roi_calculator for investment returns.

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