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

With no annotations, the description carries the full behavioral burden. It discloses that every returned value has a source and date, that absence is represented by five distinct categories (found, none, unknown, not_provided, withheld), and that up to 100 INNs are accepted. This goes well beyond the schema, though edge cases like malformed INNs are not covered.

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, front-loaded with the core purpose, followed by the key behavioral nuance about absence markers and then the input limit. Every sentence earns its place 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?

For a simple two-parameter tool with no output schema, the description covers the essential aspects: what data is returned, how absence is represented, and input constraints. It stops short of fully explaining sibling trade-offs or the exact effect of the 'want' parameter, but it is largely complete for the tool's simplicity.

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 schema already has 100% parameter description coverage for 'inn' and 'want'. The description adds meaningful parameter behavior by stating the exact limit of one hundred comma-separated INNs, reinforcing the 'inn' parameter's semantics. This exceeds the high-coverage baseline.

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 title and description clearly state the tool retrieves all known facts about a subject by INN, with each value including a source and date. This distinguishes it from siblings like prism_find, prism_nearby, and prism_needs by its focus on INN-based fact lookup, though it doesn't explicitly name alternatives.

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 clear context: use it to fetch facts for up to one hundred INNs, and the five-way absence marking helps decide whether to repeat the question or go elsewhere. It lacks explicit when-not-to-use guidance or named sibling alternatives, but the intended scenario is well implied.

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