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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds the Pro restriction and the year/as_of scoping, but it does not disclose return format, pagination, or access-failure behavior.

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?

Two dense sentences carry the full output contract and the sibling contrast without filler. The essential metrics are front-loaded before the access/alternative note.

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?

With no output schema, the description successfully conveys the report's contents and grouping dimensions. It stops short of specifying the exact response shape or how disposals are presented, and the 'Pro' restriction is hinted but not detailed.

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 coverage is 100%, and the schema already documents year, as_of, scheme, and project with defaults and enum values. The description reinforces year/as_of semantics but adds no parameter-level detail beyond the schema, meeting the baseline.

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 precisely enumerates what the report contains: net book value by category/scheme/currency at as_of, annual depreciation per currency, and disposals with gains/losses. The closing clause distinguishes it from asset_list and asset_schedule, making its purpose unmistakable despite the missing explicit verb.

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 first sentence establishes this as the annual aggregated register report, while the last sentence names the free per-asset alternatives. It does not fully spell out a when-not rule, but the contrast between a Pro aggregate report and free per-asset views is enough to route an agent correctly.

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