accounting.depreciation_declining_balance

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

Annotations already cover the safety profile (readOnly, idempotent, closed-world), and the description goes well beyond them: it discloses the salvage floor clamp, the zero-depreciation behavior once the floor is reached, the rounding mode applied, and that the rate is taken literally rather than back-derived from life_years. That last clause pre-empts a realistic caller misconception. It does not describe output shape, but an output schema exists.

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?

Four dense sentences with no filler, front-loaded with the purpose and formula before the edge-case rules. Every sentence contributes a constraint or default; it is compact for the amount of semantics it delivers.

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 six-parameter read-only calculator with an output schema, this is nearly complete: calculation rule, clamping behavior, precision and rounding defaults, and the rate-interpretation caveat are all present. The remaining gap is the meaning of life_years, which determines how many periods the schedule emits.

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%, so the description carries the full burden and only partly meets it. It fully specifies rate (Decimal string, strictly between 0 and 1), decimals (default 0) and rounding (default HALF_EVEN), and implies salvage via the floor rule, but cost and especially life_years — the schedule horizon — are never explained.

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 opens with a specific verb and resource in the declining-balance method and even states the governing formula (beginning book value x rate), which distinguishes it in substance from depreciation_straight_line and depreciation_units_of_production. It stops short of naming those siblings explicitly, so the routing is inferred from the method name rather than stated.

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 explicit when-to-use or when-not-to-use guidance and no named alternative among the sibling depreciation tools. Usage is only implied by the method stated in the first sentence, which is adequate but leaves the agent to decide between declining-balance, straight-line and units-of-production on its own.

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