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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safe/read-only nature and open-world scope are covered. The description adds only that the data is a ranked public chart; it says nothing about pagination, row counts, or freshness. With annotations carrying the safety profile and an output schema present, this is adequate but thin.

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 routing guidance second. 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?

With an output schema present the return shape needn't be described, and both optional parameters are fully documented in the schema. The description covers purpose and sibling routing, leaving only minor gaps like chart scope or default sort behavior unaddressed.

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%, and both sort and sortDir are documented with their allowed values in the schema itself. The description adds no sorting syntax or format detail, which is acceptable given the schema does the heavy lifting – 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 ("List ranked genre rows") plus the source (Box Office Mojo's public genre chart), and explicitly contrasts with the sibling boxofficemojo_genre. An agent can distinguish it from nearby genre/brand tools 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?

Names the two alternatives and the condition that selects each (boxofficemojo_genre for a single genre's titles, boxofficemojo_brands for production-brand charts). This gives clear routing context, though it doesn't explicitly state when *this* tool is the right pick (e.g., overview of all genres) beyond the contrast.

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