get_mark_price

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

With no annotations, the description carries the behavioral disclosure burden. It usefully reveals that the value is read from cache and depends on a prior subscription, but it does not specify failure behavior if the subscription is missing, staleness of the cache, or whether the call has side effects.

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 minimal and front-loaded: purpose, prerequisite, then parameter example. No sentences are wasted, and the critical subscription constraint appears immediately after the purpose.

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 one-parameter getter with an output schema available, the description covers purpose, prerequisite, and parameter meaning. It could be more complete by describing what happens when the subscription has not been made, but the tool is simple enough that this is a minor gap.

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 0%, so the description must compensate for the bare `symbol` field. It does so by defining it as a trading pair and giving a concrete format example ('BTCUSDT-PERP.BINANCE'), which is sufficient for the single parameter.

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 states a specific action ('get cached mark price') and identifies a distinct resource ('mark price') from sibling tools like get_index_price. The cache qualifier and pre-subscription note further differentiate it from direct market-data fetchers.

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?

It explicitly states the prerequisite that the agent must pre-subscribe to mark_price before calling, and characterizes the data as cached, which sets expectations for when it is appropriate. It does not name alternative tools or exclusions, so it stops 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.