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

Annotations indicate readOnlyHint=false and idempotentHint=false, so the description correctly does not contradict that this is a non-idempotent write operation. It adds context about the Bidda subscription requirement and delivery channels, but does not explain side effects like duplicate alert creation, result format, or whether the subscription is persistent. The description adds some value beyond annotations but is not rich in behavioral disclosure.

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, well-structured sentence that front-loads the purpose ('Subscribe to regulatory change alerts') and uses a colon to introduce the requirement. It covers key aspects without fluff, making it easily scannable and efficient.

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 description explains the trigger (primary source changes), the watch targets (rules/pillars), delivery channels, and the subscription requirement, which covers most operational aspects. However, there is no mention of the tool's return value or output structure, and since there is no output schema, an agent would not know what to expect. For a tool with six parameters and no output schema, this is a notable gap, but it is otherwise adequate.

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 100%, so all six parameters are already documented. The tool description reiterates the nodes/pillars distinction and email/webhook options, but adds minimal new meaning beyond the schema. Since the schema carries the parameter details, the description meets the baseline of 3 but does not exceed it.

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 verb 'Subscribe' and the resource 'regulatory change alerts', specifying that it watches specific rules or whole pillars and notifies via email or webhook. It also includes the prerequisite of an active Bidda subscription, which distinguishes it from sibling tools like get_latest_changes that likely fetch changes rather than create subscriptions. This makes the tool's purpose unambiguous.

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 clear context on when to use the tool: to subscribe to changes, and it notes the subscription requirement. However, it does not explicitly name any alternative tools or state when not to use it, such as directing agents to get_latest_changes for immediate retrieval. The context is present but lacks explicit exclusions.

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