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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false, and destructiveHint=false, so the safety profile is covered structurally. The description adds value beyond that by stating '[Public, no account needed]' — an auth prerequisite not encoded in the annotations — and by pre-declaring the return shape. It stops short of noting rate limits or behavior during degraded service, so it does not reach 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?

Three short sentences: purpose first, trigger second, contract and access note last. Every sentence carries distinct information with no restatement of the title or name.

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 parameterless liveness probe with no output schema, the description covers everything an agent needs: what it verifies, when to call it, what the response looks like ({status, version, timestamp}), and that no credentials are required.

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?

There are zero parameters, so the baseline of 4 applies and no compensating explanation is required. The description correctly avoids inventing parameter discussion for a parameterless tool.

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 names a specific verb and resource ('Check whether the WEIR AI API is up') and is unmistakably distinct from the sibling tools (check_identity, discovery, search_catalog), none of which are availability probes. An agent can identify this as a liveness check without opening the schema.

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 gives an explicit, narrow trigger: 'Use only when a call fails and you need to tell the user if WEIR AI is down.' The word 'only' also supplies an exclusion, discouraging proactive polling, which is the main misuse risk for a health endpoint.

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