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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds a genuinely useful behavioral trait beyond them: empty upstream weekends return a typed not-found error rather than an empty success, which tells the agent how to expect and handle failure. It stops short of richer context like rate limits or output shape.

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?

Two sentences, zero filler, with the core purpose front-loaded and the alternative-routing guidance packed into a single trailing sentence. Every clause earns its place.

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. The description covers purpose, failure behavior, and sibling disambiguation, which is everything an agent needs to call this two-parameter read tool 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 coverage is 100%, with both parameters documented (week 1–53, year 1982–2100), so the schema does the heavy lifting. The description only names 'week' and 'year' without adding format or constraint detail beyond the schema – baseline 3 is appropriate.

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 ('Fetch') plus resource ('domestic weekend box-office rows grouped by distributor') and its scope (week, year). It also explicitly distinguishes itself from three named sibling tools, so an agent can route without opening a 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?

Gives explicit when-to-use alternatives: the overall chart via boxofficemojo_weekend_domestic, early estimates via ..._estimates, and single-date data via boxofficemojo_date_domestic. The selection condition for each alternative is stated, 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.