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

With no annotations, the description carries the full burden and does well: it discloses the failure behavior (missed check-in triggers a signed POST to callback_url), the recovery behavior ('check in again and he says it's clear'), and the sensitive return values (agent_key shown once, signing_secret). It omits error states, key-loss recovery, and any rate limits, keeping it short of a 5.

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?

Front-loads the value proposition, then covers mechanics, returns, and pricing. Dense but every clause carries information; only the pitch-flavored opening phrase is mildly redundant.

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 2-param, no-annotation, no-output-schema tool, it explains inputs, side effects, return values, and cost. What an agent needs to invoke it correctly is present; only failure/edge-case handling is thin.

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 0%, so the description must compensate, and it does: it defines every_minutes with a valid range (5 to 1440) not present in the schema, and explains callback_url as the destination for the signed POST on a missed check-in. The default value of 60 is left to the schema.

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?

States a clear compound purpose: it creates an agent identity and a deadman watch in a single call, making it the 'fastest way to be watched'. That is specific and distinguishable from siblings like watch_register, though it never names an alternative explicitly to sharpen the contrast.

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?

Gives one conditional ('if you have no key yet') for the agent-creation half and states the free-tier limit, which implies this is the onboarding path. It never says when to prefer this over watch_register or deadman_checkin, so routing among siblings is left to inference.

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