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

Beyond the annotations (readOnlyHint=true, destructiveHint=false), the description adds substantial behavioral detail: grouping method ('face-adjacent observed portal blocks'), the non-equivalence to active portals, radius semantics ('measures representative blocks, not group centers'), result ordering and limit ('Max 25 results, nearest first then stable ID'), pagination, and citation requirements ('Cite canonicalUrl and sourceJsonUrl; never infer ownership'). It also discloses the coverage field for Nether/End. No contradiction with annotations.

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 description is information-dense but each sentence adds value. It opens with purpose, then covers grouping, dimension restrictions, radius semantics, result limits/order, pagination, and citation requirements. No filler or redundancy. The structure is logical and front-loaded.

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?

Given the tool's complexity (8 params, output schema present), the description covers purpose, scope, behavioral nuances, result limits, ordering, pagination, and citation obligations. It even warns about not inferring ownership or present-day survival. The output schema handles return structure, so the description is sufficient for an agent to call the tool correctly.

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?

With 0% schema description coverage, the description compensates for several key parameters: radius ('Radius 1..8192 horizontal blocks measures representative blocks, not group centers'), limit ('Max 25 results'), and dimension (implied by Overworld-only). It also hints at offset via nextOffset. However, it does not explain x, z, min_y, max_y, or offset in detail, so it is not fully compensating for all 8 parameters.

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 states a specific verb ('Find'), a specific resource ('historical NoCom portal groups'), and a clear scope ('near native Minecraft coordinates'). It also explicitly distinguishes these groups from what they are not ('not simultaneous active portals or verified Nether connections'), which differentiates it from sibling tools like find_nocom_storage or find_preserved_builds.

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?

The description provides clear usage context: it is Overworld-only ('Only Overworld portal observations exist; Nether/End return coverage=not_captured'), and it explains pagination behavior ('follow nextOffset with unchanged filters'). It does not explicitly name alternative tools for other dimensions or scenarios, but the Overworld restriction and the specific resource make usage conditions clear enough.

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