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 goes further with a genuinely useful behavioral trait: results are read live from the database but cached for 60 seconds, which tells the agent the metadata itself can lag. It stops short of stating cost/latency or response shape, so it is strong but not maximal.

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 useful usage guidance is front-loaded and every sentence carries information. The opening phrase largely restates the title verbatim and the backtick-heavy prose is a little denser than needed, keeping it just under top marks.

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 zero-parameter, read-only metadata endpoint with no output schema, the description supplies everything an agent needs: what is returned, how fresh it is, and the polling pattern. There is no meaningful gap left to fill.

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 takes zero parameters, so the schema (100% coverage, additionalProperties false) already fully constrains the call. The description correctly adds no parameter detail because none exists – baseline 4 applies.

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 the specific resource (per-dataset freshness metadata) and the exact fields returned: `updated_at` as the newest live timestamp in the table and `refresh_seconds` as its change cadence. This clearly separates it from the heavy data siblings such as /market/prices, /servers, and the browse_* family, so an agent can tell what it is 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 when-to-use guidance ('poll this cheap endpoint') and when-not-to ('only re-fetch a heavy payload such as /market/prices or /servers when its dataset's updated_at has moved'), plus a caching rule for reference data. Alternative tools are named and the condition that selects them is spelled out.

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