Why something doesn't work

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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, closed-world, so the safety profile is covered. The description adds genuinely new context: it explains the diagnostic branches, that fixes live in three different places (in-game, WorldAPI admin panel, this MCP server's settings), and that download links for Paper/Fabric/NeoForge are returned. It does not describe the response shape in detail, which keeps it at 4 rather than 5.

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?

Front-loaded with the action, then the failure catalogue, then the invocation triggers, then how to present results — a sensible order. The middle sentence is a long comma-chained list that is dense to parse, but each clause names a distinct diagnosable condition and earns its place.

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?

No output schema exists, so the description carries the return-value burden and does: it says what is reported (which failure plus remediation steps and download links) and how to relay it to the user. For a zero-parameter diagnostic tool this is everything an agent needs to call it and act on the result.

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?

Zero parameters, so there is no per-parameter semantics to explain and the baseline of 4 applies. The description correctly implies the tool is parameterless by framing it as an automatic check of 'this connection'.

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 — 'checks this connection and says what to fix' — then enumerates the concrete failure classes it diagnoses (no world, WorldAPI unreachable, bad token, read-only). Nothing among the ~45 sibling tools overlaps with a diagnostic/help entry point, and the description makes that distinct role obvious.

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 trigger conditions: specific error codes (unreachable, no_world, invalid_token, token_required, missing_scope), a missing tool the user needs, or a direct 'how do I set this up' question. It also implicitly excludes normal operation by tying invocation to those states.

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