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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered structurally. The description adds value beyond that by itemizing what the response contains, which matters because no output schema exists. It does not mention cost, caching, or whether the version string format is stable, keeping it out of 5 territory.

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?

Two sentences, zero filler. The returned fields lead, and the use cases follow, so an agent gets the payload description before the framing. Nothing is repeated from the title or annotations.

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 no input parameters and no output schema, the description's job is to say what comes back and why you'd want it, and it does exactly that by listing every returned field plus three valid use cases. An agent has everything needed to decide to call it and to interpret the response shape.

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 there is nothing to disambiguate and the baseline of 4 applies. The description correctly adds no parameter talk, which is appropriate rather than a gap.

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?

States a specific verb ("Return") and resource ("the current PTPGE dataset version") and then enumerates the exact payload: term count, per-level and per-group counts, license, scheme URL, server version. That is unmistakably distinct from sibling tools like ptpge_browse or ptpge_search_terms, which operate on terms rather than metadata.

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?

Names three concrete situations (version-pinning, health checks, diagnostics), which gives an agent a real decision rule for reaching for this tool. It stops short of explicitly excluding alternatives or saying when not to call it, so it lands at 4 rather than 5.

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