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

Annotations already cover safety (readOnly, non-destructive, closed-world), and the description adds substantial context beyond them: max 25 rows, the observation-vs-placement date caveat, no replacement/survival verification, no Nether/End coverage, and citation requirements. This is unusually rich disclosure that meaningfully changes how an agent interprets the results.

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?

Dense but front-loaded, leading with scope and the block-vs-structure distinction before constraints and caveats. Nearly every clause carries information, though the citation/ownership reminder is slightly softer than the rest.

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 a dedicated output schema, return-value description is unnecessary, and the definition still references canonicalUrl and sourceJsonUrl for citation. Combined with rich behavioral caveats, coverage is strong; only the undocumented 'dimension' parameter leaves a small gap.

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?

Schema coverage is 0% across 9 params, so the description must compensate, and it largely does: x/z pairing rule, kind values, Y range 0..255, radius range 1..8192, limit cap of 25, and offset via nextOffset. It does not explain 'dimension' beyond implying Overworld-only, leaving one parameter under-specified.

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 ('Query') and resource ('NoCom rare-block extraction') with concrete scope: 419 Overworld bedrock positions above Y4 and 39 End portal frame positions. It explicitly distinguishes itself from nearby siblings, noting 'these are blocks, not structures or full portals,' which separates it from find_nocom_portals and find_nocom_special_blocks.

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 clear invocation conditions: 'Supply neither x/z to discover all records, or both for a native-coordinate circle of radius 1..8192,' plus optional kind and Y filters. It also explains pagination continuation ('follow nextOffset with unchanged filters'). It does not, however, explicitly name which sibling tool to use for cluster or storage queries instead.

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