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

With readOnlyHint, idempotentHint, and destructiveHint already covering safety, the description adds useful behavioral context: output units, density basis, NIST ESTAR density-effect table inclusion, and a PDG 2024 citation. It does not describe behavior for invalid or unknown material names, which is a minor gap.

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 front-loaded with the returned property list and uses only three sentences with no obvious filler. The long first sentence is dense but appropriate given the amount of returned data it summarizes.

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?

There is no output schema, so the description carries the burden of explaining return values, and it does so by listing the properties, units, density basis, and data sources. For a one-parameter lookup tool with strong annotations, this is sufficiently complete for correct invocation.

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%, and the schema already documents the single material parameter with an example. The description repeats the name/ID instruction and adds the useful constraint of 17 available materials, but it does not enumerate or further constrain valid values.

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 identifies the resource as material properties and lists the specific quantities returned for 17 materials. However, it does not explicitly state a retrieval verb or differentiate the tool from sibling physics tools such as energy_loss or photon_attenuation.

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 instruction 'Give a material name or ID' implies how to invoke the tool, but there is no explicit guidance on when to use this lookup versus related sibling tools. Usage is therefore implied rather than directed.

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