ws_subscribe_blocks

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

With no annotations, the description carries the full burden, but it only says 'subscribe' without disclosing how notifications are delivered, whether the subscription persists, how to unsubscribe, or any side effects. This essentially restates the tool name and adds 'new block notifications', which is a minimal tautology that fails to disclose expected behavioral traits.

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 a single short sentence, which is concise and front-loaded. However, it is under-specified to the point of being a label rather than a helpful explanation, and there is no structural organization of information. It is not flagrantly verbose, so it earns a middling score.

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?

The tool is a WebSocket subscription with no output schema and no annotations, yet the description fails to explain the subscription lifecycle, such as how to receive updates (via ws_get_updates), how to unsubscribe, or that it supports specific chains (though the schema does). It is severely incomplete for a tool of this complexity, leaving the agent without critical context for correct usage.

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 fully describes the chain parameter with an enum of supported blockchains and a description ('Blockchain to monitor'), so schema coverage is 100%. The tool description adds nothing beyond this, but the baseline of 3 is appropriate since the schema already provides complete parameter semantics.

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 the action (subscribe) and the resource (new block notifications), which directly communicates the tool's purpose. It also distinguishes itself from sibling subscription tools like ws_subscribe_price, ws_subscribe_wallet, and ws_subscribe_pool by specifying 'blocks'. This is a clear, verb+resource formulation.

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 provides no guidance on when to use this tool versus alternatives, such as polling block endpoints or using other subscription tools. It does not mention that it is for real-time notifications or that updates should be received via ws_get_updates, nor does it offer any exclusions or alternative recommendations.

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