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

Given annotations already set readOnly=false and idempotent=true, the description adds useful behavior: 30-day duration, webhook firing on specific risk events, and a maximum of 10 addresses. It avoids contradiction and fills in the 'side effect' of creating an active subscription.

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 two lean sentences with no filler. The action, constraints, and alert categories are all front-loaded or directly contextual.

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?

With a complete schema and these two sentences, an agent knows what action to take and effect to expect. But the tool lacks an output schema and the description does not explain the response shape, how repeated subscriptions are handled, or any payment/cancellation details.

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?

Input schema coverage is 100%, so baseline is 3. The description repeats the address limit already in the schema and only loosely trades thresholds to alert types. It does not add meaningful parameter semantics beyond the schema definitions.

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 uses a specific verb ('Subscribe to') and names a precise resource: 30-day continuous monitoring of up to 10 EVM contract addresses. It lists concrete alert categories and clearly distinguishes this from one-time audit/triage 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?

Usage context is implied: the subscription product and alert categories suggest this is for continuous monitoring, not one-off analysis. However, it does explicitly say when to use this vs alternatives or when not to use it.

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