naep_compare_years

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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds that it 'shows whether score changes between years are statistically significant,' which is the key behavioral output, but does not detail significance thresholds, methods, or any quirks. It contributes modest context beyond annotations, so a 3 is appropriate.

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?

Three concise sentences, each with a distinct role: core operation, clarifying output, and motivating use case. The main verb and resource appear in the first two wordscd5905. No filler, no repetition of schema fields, and the structure is easy to scan.

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 read-only comparison tool with a clear description and complete parameter documentation, the essentials are all present. It could arguably add a note on output formatting (e.g., whether p-values or confidence intervals are returned), but that is not required for selection or invocation. The sibling set includes similar NAEP tools, so a bit more differentiation would raise this to a 5, but 4 is still strong.

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%, so every parameter is already documented in the input schema (e.g., 'years' format, 'subject' aliases, defaults for 'variable' and 'jurisdiction'). The tool description itself adds no additional parameter guidance, which is acceptable given complete schema coverage. Baseline of 3 applies.

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 identifies a specific verb ('Compare') and a precise resource ('NAEP scores across assessment years'), and further specifies the distinguishing value-add: significance testing. This clearly separates it from siblings like naep_scores (single-year data) and naep_compare_states (comparison by state) without requiring schema inspection.

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 a concrete, well-known use case ('Great for tracking the COVID learning loss and recovery'), which tells the agent when to select this tool. It does not explicitly name alternative tools or exclusions, but the context is clear enough to route an agent toward this vs. a single-year score tool. A small deduction for not explicitly mentioning when not to use it.

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