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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world behavior. The description adds useful output context—per-item and total valuation plus the books' Inventory balance—but does not disclose caveats, data freshness, or response shape beyond that.

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 definition is a single efficient sentence with no redundant clauses. The key scope—valuation by day, per item and total, beside book balance—is front-loaded.

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 read-only report with one optional parameter and no output schema, the description adequately explains what the report contains. It could be slightly more complete by explicitly distinguishing the valuation view from stock-quantity views.

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%, so the single as_of parameter is fully documented by the schema itself, including its default and ISO format. The description's phrase 'on a day' aligns with as_of but adds no syntax or semantic detail beyond the schema.

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 resource and output: stock worth on a given day, per item and in total, alongside the derived Inventory balance. It does not explicitly name or contrast with sibling tools like inv_stock or inv_item_stock, so sibling differentiation is left implicit.

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?

Usage is implied by 'on a day' and the default-to-today parameter, suggesting a point-in-time valuation report. However, there is no explicit guidance on when to use this tool versus inv_stock, inv_item_stock, or inv_cost_of_sales.

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