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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds meaningful context beyond them: the response is public service metadata, it exposes build date and source commit, and it contains no player or game records, which tells the agent this is a harmless, non-sensitive endpoint.

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?

It is a single semicolon-joined sentence that front-loads the payload (build date, source commit) and follows with the use case and the scope exclusion. No wording is redundant for a tool of this simplicity.

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-argument read-only tool with annotations declaring its safety profile and an output schema documenting return values, the description covers everything an agent needs: what it returns, what it is for, and what it does not expose.

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 no parameters, so there is nothing for the description to clarify; the baseline for a zero-parameter tool applies. The description correctly signals that the call needs no arguments by framing it as plain service metadata retrieval.

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 a specific verb ('Get') and a precise resource ('deployed Lichess server build date and source commit'), then scopes it as public service metadata with no player or game records. That scope statement separates it from the other Lichess tools (puzzle, tablebase, cloud_eval), so an agent can identify it without opening the 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 concrete usage contexts: diagnostics or comparing API releases. There is no explicit 'do not use when' clause or named alternative, but with zero parameters and no near-equivalent sibling in the list, the context is sufficient to select it correctly.

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