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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered and the closing 'Read-only' merely restates it. The description does add value beyond annotations by noting prices 'follow the live model price table,' warning the agent that returned values are time-sensitive even though the call is idempotent and that stale/from-memory figures are unreliable.

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, front-loaded with the resource and its contents, then the operational directive. Every clause carries information: the enumeration tells the agent what to expect back, and the live-price note prevents a real failure mode.

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?

There is no output schema, yet the description effectively describes the return content by listing the price categories and units (USD and credits). With annotations covering safety and no parameters to document, nothing an agent needs in order to call this correctly 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?

The tool takes no parameters, so the baseline is 4; there is no parameter surface the description needed to explain and it does not waste space pretending otherwise.

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?

States a specific verb and resource ('Current Cast prices in USD and credits') and then enumerates exactly what price categories are covered: Season 1 weekly passes, agent credit packs, Premium, per-video-length credit costs, and new-character cost. An agent knows precisely what it gets without opening the schema, and the scope is clearly distinct from the sibling tools (create_video_link, get_showcase, list_characters).

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?

Explicitly says to 'call this instead of quoting from memory,' which is a clear when-to-use directive and names the alternative behavior being displaced. It lacks explicit when-not conditions or routing among the sibling tools, but for a zero-parameter price lookup there is little ambiguity left.

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