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

With no annotations provided, the description carries the burden of behavioral disclosure. It discloses the no-op behavior for the already-active page, the failure mode for out-of-range indices, and the persistent effect of changing the target for subsequent content tools. It does not mention side effects beyond the active-page change, but that appears to be the complete behavior.

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?

The description is compact, well-organized, and front-loads the core purpose in the first sentence. It then explains the scope of effect, addressing mechanism, and edge cases in a few dense sentences without redundancy.

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?

For a simple two-parameter tool with no output schema, the description fully covers what an agent needs: what the tool does, what page indices mean, how to obtain project ID, and the edge-case behaviors. There is no missing context that would prevent correct invocation.

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 the schema already documents both parameters. The description reinforces that 'index' is 0-based and references describe_video's pages block, adding helpful context for deriving the index. It does not deeply elaborate on projectId because the schema already explains its role and origin.

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?

The description clearly states the tool's action ('Switch which page is ACTIVE') and specifies that it targets the page that content tools read and write. It distinguishes itself by explaining the active-page mechanism, which is unique among siblings like add_page and delete_page.

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 explains when to use the tool (to change the target of subsequent content tools) and provides useful conditions: selecting an already-active page is a no-op, and out-of-range indices fail. It does not explicitly name alternative tools, but none are directly alternatives because this is the only page-selection tool.

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