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. It adds the core behavior of even depreciation, but does not disclose edge cases (e.g., yearsElapsed beyond useful life) or return format. It is adequate but not rich.

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 a single concise sentence that front-loads the core concept. There is zero waste; every word contributes to understanding the tool's purpose.

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 financial calculator with a fully documented input schema and an output schema, the description is sufficiently complete. It explains the concept and the presence of an output schema means return values are covered elsewhere. Minor gaps like parameter constraints or expected value ranges are not critical.

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?

The schema provides 100% coverage of the four parameters with clear descriptions. The description adds general context about the method but does not elaborate on parameter specifics beyond what the schema already contains. Baseline 3 is appropriate.

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 the tool's function: it calculates straight-line depreciation by evenly spreading value decline to a salvage value over a useful life. This distinguishes it from other depreciation methods by naming the specific approach. It is more specific than a mere restatement of the title.

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 guidance is given on when to use this tool versus alternatives like declining-balance or sum-of-years-digits. Given the many depreciation-related sibling tools, the description lacks explicit usage context or exclusions.

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