health_check

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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered; the description earns credit for adding behavior annotations cannot express: the upstream endpoint (GET /api/v4/version) and, notably, that version lookup failures omit those fields rather than failing the call. That partial-degradation contract is exactly the kind of context an agent needs and cannot get from structured fields.

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, zero filler, and the always-present field is front-loaded before the conditional fields. Every clause carries distinct information: what is checked, what is always returned, what is conditionally returned, and what happens on failure.

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?

There is no output schema, and the description compensates by enumerating the returned fields (mcp_server_version always; version, revision, enterprise when authenticated) and the failure mode. It stops short of explaining what the response looks like when unauthenticated beyond 'always includes mcp_server_version', which leaves a small gap for a diagnostic tool.

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% with a single optional jmespath parameter that the schema documents fully with its own description. The tool description adds nothing about the parameter, so the baseline 3 applies — the schema does all the work.

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 opens with a specific verb-plus-resource statement ('Check auth and versions') and immediately clarifies what is always returned versus conditionally returned. It is clearly not a data-fetching sibling, though it never distinguishes itself from whoami, the other auth/identity-adjacent tool in the sibling list.

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?

Usage is only implied: an agent can infer this is the tool to call to verify credentials or server version, and the phrase 'When authenticated' hints at a pre-flight role. There is no explicit when-to-use, when-not-to-use, or named alternative (e.g. whoami) that would raise this above implied guidance.

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