Server health and data-source catalog

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the description does not need to restate safety. It adds value by disclosing the tool doubles as the canonical version/health endpoint and by explaining the semantics of the returned fields (e.g., freshness and cache_ttl_seconds for cache decisions). This complements annotations without contradiction.

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 efficiently structured: a one-line summary, a paragraph explaining the dual purpose, and a clear list of return fields. Every sentence contributes meaning (e.g., how to use the freshness info, what the response contains). It is front-loaded and not padded.

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?

Despite having an output schema, the description provides sufficient context: it explains the tool's role, the meaning of freshness/TTLs for practical decisions, and enumerates the exact return fields in the sources list. The tool is simple (no params), and the description covers all necessary aspects for an agent to invoke it correctly.

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 zero parameters, so the baseline is 4. The description adds no parameter-specific semantics because there are none, and the schema already covers everything (100% coverage with empty properties). It appropriately avoids inventing unnecessary parameter details.

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 explicitly states 'Server health + data-source catalog probe' and details the exact outputs (server_version, sources catalog with TTLs, freshness). This clearly distinguishes it from sibling data-retrieval tools which focus on specific datasets (e.g., earthquakes, weather). The verb 'probe' and resource scope are precise.

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?

The description provides clear use cases: confirming server release via server_version and deciding whether a stale cached response is acceptable based on source freshness/TTLs. It does not explicitly name alternative tools or state when not to use it, but the context strongly implies its unique role as a health/catalog probe among data tools.

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