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

Annotations already declare a safe read (readOnly, non-destructive), and the description adds substantial behavior beyond them: pagination order (nearest first then ID), page cap of 25, nextOffset continuation with unchanged filters, and the Nether not_captured outcome. This is exactly the extra operational context annotations cannot carry.

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?

Purpose is front-loaded and each sentence adds a rule (semantics, pagination, dimension, workflow). It is dense but earns its length, though a few phrasings ('Roots are not centers, bases or players') are terse enough to require a second read.

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 6-param, paginated, dimension-aware query with an output schema already documenting returns, the description covers behavior, pagination, and dimension caveats well. The main omission is explicit semantics for the required x/z, but otherwise an agent has enough to invoke it 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?

Schema coverage is 0%, so the description carries the burden and mostly does: it constrains radius (1..8192 blocks), explains dimension behavior, and describes offset/limit through the pagination rules. x and z are only implied as the circle center ('native horizontal circle') and never explicitly defined, leaving a small gap.

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 ('Page through historical NoCom DBSCAN cluster roots') and immediately disambiguates the entity by excluding centers, bases, and players. Combined with the NoCom-specific naming, an agent can separate it from siblings like find_nocom_portals or find_locations_near 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?

Gives concrete conditions: dimension matters (Overworld/End capture roots, Nether returns not_captured), and workflow guidance such as 'Use footprintJsonUrl for all member chunks' and 'Resolve named locations first.' It stops short of naming a specific alternative tool, so it is clear context without explicit exclusions.

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