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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, so the bar is lower. The description adds that the tool 'estimates' rather than retrieves actual data and lists output categories (direct costs, regulatory fines, etc.), which is useful context. However, it doesn't disclose limitations, data sources, or calculation methodology, so it remains a moderately transparent description.

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 three sentences plus a keyword list, front-loaded with the core purpose. Every sentence earns its place—purpose, inputs/outputs, and use cases—with no filler or redundancy.

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?

Given the output schema exists, return values need no explanation. The description covers purpose, inputs, outputs, and ideal use cases, which is sufficient for a read-only estimation tool. It lacks caveats or limitations, but the description is complete enough for an agent to decide when to invoke the tool.

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 input schema has 100% description coverage, so each parameter is already documented. The description mentions 'breach size, industry sector, and affected jurisdictions,' which maps to records_lost, industry, and jurisdictions, but adds no new meaning beyond what the schema provides. 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: 'Estimates financial impact of a data breach across three jurisdictions (US, EU, UK) for CFO strategic planning.' This specific verb+resource+scope distinguishes it from general data breach tools. It also enumerates inputs and outputs, making the purpose unmistakable.

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 provides clear context with 'Ideal for cross-border risk assessment, financial contingency planning, and board-level reporting.' This tells when to use it, but it does not mention alternatives or explicit exclusions, so it falls short of a 5.

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