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

Annotations already declare readOnlyHint=true and destructiveHint=falsecompress. The description adds useful behavioral context: cost per call ($0.02 USDC), source (HFMA/CMS composite), and an example of typical output values (18% savings, 22% leakage). These go beyond annotations and help the agent understand what the call will deliver.

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 well-structured and front-loaded with the use case, then the return contents, then an illustrative example, followed by source and cost. Every sentence earns its place; there is no filler.

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?

Despite a rich description, it omits any explanation of the 'category' parameter, its optionality, or how it affects the benchmark output. Since the parameter is undocumented in the schema, this is a significant gap. The tool has no output schema, so the description should also clarify the shape of returns, which it only does with a single example.

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 one optional 'category' parameter with 0% schema description coverage, so the description must compensate. It does not explicitly explain the parameter, its allowed values, or its effect on results. The example mentions 'Acute care GPO median savings' which weakly implies category could filter by healthcare segment, but this is not clarified.

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 returns GPO savings percentage, leakage rate, and top savings categories, and specifies when to use it (benchmarking GPO contract performance, hospital board cost reduction case). The verb 'returns' and resource are explicit and distinguish this from generic benchmarks in the sibling list.

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?

Explicitly states use cases ('benchmarking GPO contract performance', 'building a supply chain cost reduction case for a hospital board'). However, it does not name alternative sibling tools or mention when not to use them, so it lacks exclusions but provides clear context.

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