youtube_analytics_day_of_week

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

With no annotations, the description carries the full burden. It discloses the internal behavior ('Fetches daily data and aggregates by weekday') and provides defaults for the date parameters. The read-only nature is implied by 'Get,' but it doesn't explicitly state auth requirements or the exact metrics returned.

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 succinct, with a front-loaded summary, a relevant use case, and a clean argument list. Every sentence earns its place, with no redundant or verbose content.

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, so the description should explain what the agent will receive, but 'performance' is vague and doesn't specify which metrics (e.g., views, watch time) are aggregated. The description covers the core functionality and params but lacks details about return values and potential edge cases, making completeness only average.

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?

The description adds rich meaning beyond the schema: it specifies the YYYY-MM-DD format and the defaults (90 days ago and today) for start_date and end_date. Since the schema coverage is 0%, this fully compensates and gives the agent necessary usage details.

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 uses a specific verb ('Get') and clear resource ('aggregated performance by day of week') and explains the purpose with 'show which days perform best.' This clearly distinguishes it from other analytics tools like youtube_analytics_daily or youtube_analytics_overview.

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 provides a clear use case ('Useful for scheduling uploads') that indicates when to use the tool. However, it doesn't explicitly mention alternatives or when not to use it, so it falls short of a 5.

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