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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint=false, so safety is covered. The description adds behavior the annotations cannot express: exactly one liveness round-trip, and the failure contract — it never errors on an unreachable API but returns healthy=false instead. That non-obvious error semantics is the kind of disclosure that changes how an agent handles the response.

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 sentences, front-loaded with the primary action, then the return shape, then the failure contract, then the sibling routing. No filler and every clause carries information an agent needs.

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?

With zero params, a rich output schema, and full anisotropy of annotations, the description covers everything material: purpose, ordering, return fields, error behavior, and alternative tool. Nothing needed to call it correctly is missing.

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?

Zero parameters, so per the rubric the baseline is 4. The description does useful work by enumerating the returned metadata fields (name, version, API base, tool_count, healthy), but there are no parameters whose semantics could be enriched.

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 states a specific verb and resource (confirm the ESG Hub MCP server is reachable; return version and API base) and immediately names the sibling to use instead for other data: 'For sections, pillars, source domains, or totals use get_esg_metadata.' An agent can distinguish it from all 14 siblings without opening a 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 explicit ordering guidance ('Use this first') plus a clear routing rule away from itself to get_esg_metadata for richer ESG data. Both the when-to-use and the when-to-use-something-else cases are covered.

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