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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the notion of 'normalized grouped rows', hinting at output shape, but says nothing about grouping keys, coverage, or freshness, and the output schema already carries the return structure.

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?

A single front-loaded sentence with no filler, though 'normalized grouped rows' is jargon that consumes space without adding actionable meaning.

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?

Because an output schema exists, the description need not explain return values, and for a simple two-parameter fetch tool it is mostly adequate. The main gap is the total absence of parameter documentation for required year/month inputs.

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 0% and the description never mentions the year/month parameters, their format, or valid ranges. With two required integer parameters and no schema documentation, the description should compensate but does not.

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 (returns) and resource (Box Office Mojo's public domestic release schedule), so an agent knows it fetches schedule data. However, 'normalized grouped rows' is vague jargon that doesn't clarify the grouping, and it does not distinguish itself from siblings like boxofficemojo_calendar_date or boxofficemojo_calendar_changes.

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 no when-to-use guidance and no alternatives, despite three closely-named calendar siblings (calendar_date, calendar_changes) that an agent must choose between. The selection condition is left entirely to inference from the name.

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