CS_Photo

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

No annotations are provided, so the description carries the full burden. It states the inputs (Z, E) and output unit, but does not disclose potential restrictions (e.g., valid E range, behavior for out-of-range values, or return structure). For a calculation tool, this is adequate but minimal.

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 extremely concise: one-line purpose plus two lines for parameters. Every sentence is informative, and there is no extraneous text. This is a model of efficiency.

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 existence of an output schema (not shown), the description need not explain return values. It covers the essential input constraints. However, missing details like valid energy range or error handling reduce completeness slightly. For a simple two-param tool, it is mostly complete.

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 description adds value beyond the input schema by providing units for E ('keV') and the range for Z ('1-120'). With 0% schema coverage, this is helpful. However, it does not specify that E must be positive or give precision hints. For two parameters, this is good but not exhaustive.

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 specifies the tool's function: 'Calculate the photoionization cross section of an element (cm2/g)'. It includes the unit and the two required parameters (Z and E). This distinguishes it from sibling tools (e.g., CS_Rayl, CS_Compt) that calculate other cross sections.

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 no guidance on when to use this tool versus alternatives. There are many sibling tools for different cross sections, but no explicit when/when-not or context for choosing CS_Photo. The user must infer usage from the name alone.

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