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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false. The description reinforces idempotency and adds value beyond the annotations with 'no side effects' and a latency bound ('< 50 ms'), plus the staleness-check workflow. It does not add auth or rate-limit context, but the annotation coverage is strong, so a 4 is warranted.

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 return fields and the once-per-session guidance are front-loaded and efficient. The leading 'Calculation, not advice. Verify with a professional before acting.' is boilerplate disclaimer that is relevant but not strictly about this tool, keeping it short of a perfect 5.

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?

There is no output schema, so the description carries the return-value burden, and it lists all returned fields explicitly. For a zero-parameter, read-only diagnostic tool, this is fully complete.

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 per the rubric the baseline is 4. The description correctly adds no parameter guidance because none is needed, and schema coverage is 100%.

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 and resource ('Returns metadata about the running Senaro MCP server') and enumerates exactly what is returned: version, contract version, build commit, build timestamp, and supported tools. This clearly distinguishes it from the financial-calculation siblings, none of which are server/diagnostic tools.

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?

Gives explicit timing ('Call this once per session before drafting any content') and the reason ('to verify the running process is not stale after a deploy'). It even prescribes a conditional action on the result: if server_version is below the required minimum, STOP and ask the user to restart. Nothing is left to inference.

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