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

Annotations already declare readOnlyHint=false (mutation) and destructiveHint=false. The description adds valuable context: it requires a positive prepaid balance and that first data lands within 24-72h, implying asynchronous processing. It does not contradict annotations and provides a behavioral expectation beyond the flags.

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 three tight sentences with zero fluff. The core purpose is front-loaded, and the prerequisite and latency are provided in subsequent sentences. Every sentence earns its place, making it easy for an agent to parse quickly.

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 simple one-parameter write tool with no output schema, the description covers the essential context: what it does, the prerequisite (balance), and the expected delay. It does not mention error handling or what happens if the domain is already monitored, but these are minor gaps given the tool's simplicity and the annotations already present.

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 fully describes the single parameter 'domain' with 'Domain to start monitoring' (100% coverage). The description adds no additional detail about format, validity constraints, or examples. Since the schema carries the burden, a baseline of 3 is appropriate.

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: 'add a domain to monitoring' with a specific resource (domain) and a distinct verb (add/request). It distinguishes itself from the sibling read-only get_* tools by framing this as a write/request operation. The purpose is unambiguous and immediately actionable.

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 explains the prerequisites (account with positive prepaid balance) and gives a latency expectation, but it does not explicitly say when to use this tool versus alternatives or when not to use it. The sibling tools are all read operations, so the context implies this is the write path, but no explicit routing guidance is provided.

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