health_check

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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds valuable context beyond that: it states that version lookup failures do not fail the health check and those fields are omitted, and it clarifies it does not mutate state. It does not contradict the annotations.

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 moderately lengthy but well-structured: it leads with the primary purpose, explains version behavior, provides usage guidance, and closes with non-mutation. Each sentence adds information; no filler. It could be tightened slightly but is certainly not bloated.

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 tool with no output schema, the description covers what the tool returns ('server/authentication status plus GitLab version details when available') and its failure semantics. An agent has enough to call it correctly. It does not specify exact response structure, but that is not required given the absence of an output schema.

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 tool has no parameters (schema coverage 100%), so the baseline is 4. The description correctly notes that it accepts no input and focuses on what the call does. It doesn't need to add parameter details since none exist.

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 tool verifies server connectivity and authentication, and also reports GitLab version details. It uses specific verbs and resources (server status, authentication, version) and distinguishes itself from whoami by contrasting the goal (server status vs user identity). This makes its purpose unambiguous.

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 explicitly says 'Use this to verify server connectivity and authentication before making GitLab requests; use `whoami` when the authenticated user's identity is the goal.' This provides direct when-to-use and when-not-to-use guidance, naming the alternative tool. No inference is needed.

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