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

The annotations already mark this as readOnlyHint and openWorldHint, so the main behavioral risks are already covered. The description adds genuinely useful context beyond the annotations: the approximate count of ~15, the RSS feed source, and the speed/cost positioning. These explain important constraints (approximate count, feed-based freshness) that an agent would otherwise not know.

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 two sentences with no filler. The first sentence front-loads the core action and resource; the second adds distinct positioning relative to alternatives. Every word earns its place.

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 single-parameter, read-only tool with a rich output schema, the description combined with the schema and annotations is complete. It tells the agent what it does, what it returns approximately, how to invoke it, and why it is the right choice for a quick recent-videos check. Nothing an agent needs to call it successfully is missing.

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 single 'name' parameter is already well documented with accepted formats (@handle, channel name, UC... ID, or URL). The description reinforces the parameter's role ('of a channel from its RSS feed') but doesn't add meaning beyond what the schema provides, so baseline 3 is appropriate.

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 a specific verb ('Get'), a specific resource ('the ~15 most recent videos of a channel'), and a source ('from its RSS feed'). It also distinguishes itself from siblings by describing how it differs — 'fastest and cheapest way to check what a channel published recently' — which gives a unique identity among the list/search variants.

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 gives a clear usage context: use this when you need a fast, cheap check of a channel's recent uploads. It implies contrast with heavier sibling tools like list_channel_videos or search_channel_videos, but it does not explicitly state when to avoid this tool or name alternatives, so it falls short of a full 5.

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