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

The annotations already mark it read-only; the description adds valuable behavioral details such as the hard limit of 100 per call and the server_timestamp walk-forward mechanism to avoid gaps. This goes beyond what annotations provide.

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 concise: four short sentences, each serving a distinct purpose—identifying as a polling tool, describing the core behavior, giving iteration guidance, and stating the limit. No redundant or vague wording.

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 polling endpoint, the description covers the essential behavior, iteration, and limit. It could mention that asset and signal_type are filters, but the presence of an output schema covers return value details, so 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?

The schema has 0% description coverage, so the description must compensate. It thoroughly explains the required since_timestamp parameter (unix epoch seconds, walk forward), but does not clarify that asset and signal_type are optional filters, leaving their semantics to the schema titles alone.

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 tool as a polling alternative to the /stream WebSocket, returning active signals with timestamp greater than a provided since_timestamp. This specific verb+resource+scope distinguishes it from other signal-fetching siblings.

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 frames the tool as a polling alternative to the WebSocket, giving a clear context for use. It also provides a precise iteration pattern ('Use the returned server_timestamp as the next call's since_timestamp') and notes the hard limit per call, covering both when and how to use it.

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