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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context beyond that: the data source (NAIC annual statistical report) and the per-call cost ($0.02 USDC). It does not cover response shape or update cadence, but for a read-only benchmark lookup the added context is meaningful.

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 effective sentences: metrics, source, audience/cost. The most identifying information is front-loaded, and there is no filler. It could be slightly tighter by combining audience and cost, but each sentence carries useful content.

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 two-parameter enum-based read-only tool, the description covers the domain, metrics, source, audience, and cost. However, there is no output schema and no explanation of company_size or the response structure, so the agent still has to infer part of the expected result format.

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 must compensate. It explains that results are broken down 'by line of business,' giving some meaning to line_of_business, but it never mentions company_size, leaving a required-selectable parameter without explanatory context. The agent cannot tell what company_size represents or how it affects output.

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 names the resource (insurance financial performance benchmarks) and enumerates the exact metrics returned: combined ratio, loss ratio, expense ratio, and reserve adequacy. It is scoped by line of business, which separates it from the many other get_*_benchmark siblings in the domain.

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 gives explicit target use cases: insurance CFOs, actuaries, and analysts reviewing underwriting performance. It does not name alternative tools or exclusion criteria, but the insurance-specific framing is enough to imply when it should be chosen over unrelated benchmarks.

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