naep_available_variables

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

Annotations already declare readOnlyHint=true, so the tool's safety profile is known. The description adds that it returns variable names, short labels, and long labels, which is useful. However, it does not mention pagination, ordering, or any potential limitations, so it only adds marginal context beyond the annotation.

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, each serving a clear purpose: stating what it does, when to use it, and what it returns. There is no redundant or filler content, making it efficient and well-structured.

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 relatively simple discovery tool, the description is adequately complete. It covers the tool's purpose, usage context, and output structure. The full parameter schema and readOnly annotation fill in remaining details, so the agent has enough context to invoke it correctly.

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% for all three parameters (subject, cohort, years), and the description does not add additional semantics beyond the schema. It refers to the parameters generically ('subject, cohort, and year') without providing extra format or constraint details.

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 lists available independent variables for a NAEP subject, cohort, and year, which is a specific verb+resource combination. It also distinguishes itself from siblings like naep_scores by noting it is for discovering variables before querying scores.

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 explicitly says 'Use this to discover what demographic/survey variables are available before querying scores,' which provides clear usage context. It does not explicitly list alternatives or exclusion cases, but the instruction is direct and actionable.

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