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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds modest context ('public ... changes page', 'grouped rows') but says nothing about pagination bounds, freshness, or auth beyond what the schema's allowed values already imply.

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, both load-bearing: the first defines the resource and the pagination parameter, the second routes the agent to alternatives. No waste.

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 to describe return shape and annotations covering the read/open-world profile, the description supplies everything else needed to invoke correctly: purpose, pagination semantics, and sibling disambiguation.

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 already 100% (offset with allowed values enumerated), so the baseline is 3. The description adds functional meaning beyond the raw enum by explaining that offset 'advances through the change list', clarifying its role as a pagination cursor.

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) and resource (grouped rows from Box Office Mojo's domestic release-schedule changes page), and explicitly distinguishes itself from boxofficemojo_calendar and boxofficemojo_calendar_date. An agent can tell exactly what this returns 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 two alternative siblings and the conditions that select them ('current schedule' vs 'one date'), leaving nothing to inference about when to reach for this tool instead.

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