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

Annotations already declare readOnlyHint and openWorldHint. The description adds real behavioral context beyond them: it discloses the upstream not-found behavior for empty weekends and clarifies that the payload compares estimated and actual rows. It stops short of documenting pagination or auth, but with annotations covering the safety profile this is solid.

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 core purpose followed by input constraints, failure behavior, and the alternative tool. Every sentence carries distinct information.

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?

An output schema exists, so return values need not be explained. For a two-parameter read tool, the description covers purpose, inputs, edge-case behavior, and sibling routing, leaving no material gap.

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 year (1982-2100) and week (1-53) are already fully documented in the schema. The description restates the same ranges without adding format or semantic detail beyond it, so the baseline 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?

States a specific verb and resource: comparing estimated vs actual domestic box-office rows for a single weekend. It distinguishes itself from the sibling boxofficemojo_weekend_domestic by naming that alternative explicitly, so an agent can route correctly without opening either schema.

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?

Provides explicit routing: use this tool for estimated-vs-actual comparison, and use boxofficemojo_weekend_domestic when you want the domestic weekend chart. It also notes the empty-weekend not-found condition, leaving nothing to inference.

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