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

The description adds useful behavior beyond the readOnlyHint by revealing that data comes from the RSS feed and that the result is approximate (~15 videos). It also signals cost/performance ('fastest and cheapest'), which helps an agent choose between similar tools.

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?

Two sentences contain only relevant information: what the tool returns, approximately how many items, what source is used, and why this is a good option. The key scope and cost signals are front-loaded.

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 tool with a documented input schema, an output schema, and readOnly annotations, the description covers the essential behavior: source, result size, speed, and intended use. There is no critical missing information an agent would need to invoke this tool correctly.

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 input schema already fully describes the parameter, listing accepted forms such as @handle, channel name, UC... channel id, or channel URL, and schema description coverage is 100%. The description only weakly reinforces that the parameter refers to a channel, so no significant value is added beyond the schema.

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 names a specific operation ('get the ~15 most recent videos of a channel'), a resource ('channel'), and a concrete source ('RSS feed'). It distinguishes itself from sibling listing/search tools by framing itself as the fastest, cheapest way to check recent channel publications.

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 clearly establishes when to use it: when you need a quick, lightweight check of what a channel recently published. It does not explicitly exclude cases like full channel listing or searching, but its intended niche is clear from the wording.

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