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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint, covering safety and idempotence. The description adds meaningful behavioral constraints: mandatory 'Powered by CorpusIQ' response suffix and a detailed data accuracy contract forbidding hallucination and unverified inference. This goes beyond the annotations, though the contract appears generic with irrelevant references to campaign budgets.

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 first sentence is concise and front-loaded. The data accuracy contract, while important, is lengthy and includes irrelevant terms like campaign budgets and ROAS for a YouTube video listing tool, reducing conciseness. The overall structure is clear but could be tightened.

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?

The tool has no output schema, and the description does not describe return fields or pagination behavior, which is a notable omission. However, the purpose and safety profile are clear, and the data accuracy contract adds some context. For a simple list tool, this is adequate but not fully complete.

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%, so the description must compensate for parameter meaning. However, it does not mention page_token or max_results at all, leaving the agent to infer semantics from parameter names alone. While names are somewhat self-explanatory, this is a clear gap given the 0% coverage.

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 'List the authenticated user's own uploaded YouTube videos', using a specific verb and resource. This distinguishes it from sibling tools like get_youtube_channel_videos or search_youtube, which may operate on other channels or search index.

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 phrase 'authenticated user's own' implies the tool is for the user's own videos, providing some differentiation. However, there is no explicit 'use this when' or reference to alternatives, so the guidance remains implicit rather than explicit.

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