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

With no annotations, the description carries the full burden. It implies a read-only operation via 'Retrieves' but fails to mention authentication requirements, rate limits, error behavior, or what 'detailed information' includes. This is minimal disclosure.

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 a single sentence plus two short metadata fragments. It is front-loaded with the main purpose and contains no filler. While concise, it sacrifices informative depth.

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 is simple, but with no output schema, the description should hint at what fields are returned. 'Detailed information' is vague and does not specify whether it includes statistics, branding, or other channel metadata. Also lacks any usage constraints, making the description incomplete for an agent to fully understand the return value.

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 parameters have clear descriptions in the schema. The description does not add any new parameter semantics, but per the rubric, a baseline of 3 is appropriate when the schema already documents all parameters.

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 identifies the action ('Retrieves detailed information') and the resource ('a specific YouTube channel'), which distinguishes it from sibling tools that retrieve channel videos, playlists, or posts. It does not explicitly name alternatives, but the verb and resource are specific enough.

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?

No guidance is provided on when to use this tool versus alternatives like `get_youtube_v3_channel_videos` or `get_youtube_v3_channel_id_from_handle`. The description only includes group and billing metadata, offering no context about usage scenarios, prerequisites, or exclusions.

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