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

Beyond the annotations (readOnlyHint=false, openWorldHint=true, idempotentHint=true), the description discloses meaningful behavior: AgentMsgr sends one test call immediately and reports the result, the wake call carries no message text and only instructs the agent to call get_new_messages, and a shared connection requires the agent_key in every call. These are exactly the side effects and privacy constraints an agent needs before invoking a registration tool that reaches out to a third-party endpoint.

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 conditional purpose is front-loaded in the first sentence, and each subsequent sentence contributes a distinct fact (no message text, immediate test call, shared-connection key). Slightly conversational phrasing ('give it here') and the trailing shared-connection note make it a bit less tight than it could be, but there is no filler.

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 simple three-parameter registration with no output schema, and the description covers the important behavioral facts (test call, payload privacy, key handling) and the annotations cover safety and idempotency. It does not say whether an existing wake link is replaced or how to remove one, which would be the last missing piece.

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 coverage is 100%, so the base expectation is a 3, but the description adds context the schema lacks: it frames the url/key pair as 'an HTTPS address, often with a key or token' and explains that agent_key must be included in every call because of the shared connection. That reinforces parameter roles rather than merely restating field descriptions.

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 makes clear that this registers an HTTPS webhook/trigger that AgentMsgr will call when a message is waiting for the agent. It is a specific setup action with a concrete resource (the wake link), though the phrasing 'give it here' is conversational rather than a crisp verb+resource statement.

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 states a clear condition for use: 'If your platform has a webhook or trigger that starts you (an HTTPS address, often with a key or token), give it here.' It does not state what to do if the platform lacks such a trigger, nor does it name an alternative path, so it stops short of full when/when-not guidance.

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