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

Annotations already establish readOnlyHint=true and openWorldHint=false, so safety and closed-world scope are covered. The description usefully adds cost ('Free') and signals that the response includes a lookup-needed determination, but says nothing about the shape of that answer or about how the optional inputs change the verdict.

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 short sentences, front-loaded with the key gating instruction and free of redundant restatement of the title. The leading 'Free.' fragment is a touch clipped but carries real information about cost.

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 describing what comes back; it does so only at a high level. For a four-parameter rule engine where two optional parameters materially alter the answer, the definition leaves the agent guessing about input impact and result format.

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 25% — only 'year' is documented in the schema. The description adds meaning for the work-type parameter ('type of work' affects which rule applies), but leaves work_for_hire and author_death_year unaddressed, even though author death year is central to life-plus-term rule selection.

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 names a specific resource and result: given a year (and work type), it returns the applicable US copyright rule plus whether a records lookup is needed. It implicitly separates itself from the records-lookup siblings by saying many years are 'settled by the rules alone', though it never names an alternative tool outright.

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?

'Call this first when you only know the year' is explicit routing guidance for the entry-point case, and 'many years are settled by the rules alone' tells the agent when this tool suffices. It stops short of stating the converse (when to skip this and go straight to a records search), so the when-not is only implied.

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