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

Annotations already declare readOnlyHint and idempotentHint, so the description does not need to repeat those safety traits. It adds value by specifying the return values (units accumulated, total invested, average cost, final value), which goes beyond the bare schema. No contradictions with annotations.

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 two short sentences, front-loaded with the core concept and followed by the outputs. No unnecessary words or repetition.

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 two-parameter tool with full schema coverage and an output schema available, the description is sufficient. It states the input pattern and the calculated results, making the tool's behavior clear. The presence of an output schema means return value details do not need to be exhaustively repeated.

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 descriptions cover both parameters fully (price at each period and fixed investment amount). The description does not add additional parameter-level detail beyond restating the concept, so the baseline score of 3 applies given the 100% schema coverage.

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 clearly states that the tool calculates dollar-cost averaging by buying a fixed amount each period at the given prices, and lists the computed outputs (units accumulated, total invested, average cost, final value). This specific verb+resource distinguishes it from the many other financial calculators in the sibling list.

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 description explains the concept of dollar-cost averaging but does not explicitly state when to use this tool over alternatives such as future-value or compound-interest. It implies usage for DCA calculations but lacks explicit exclusions or alternative suggestions.

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