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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description goes beyond them to disclose a concrete failure mode: passing the wrong script_type yields false-positive errors, illustrated with hook-name examples (on_right_click vs on_npc_interact). That is real behavioral context an agent cannot get from 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?

Front-loaded with the core action and the IMPORTANT callout before the per-type enumeration. The lengthy list of script types partially restates the schema enum, making it denser than strictly necessary, but each clause carries actionable mapping information.

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 read-only validator with no output schema, the description covers what to pass, when, and the dominant failure mode. It doesn't say what the validation response looks like (error list shape), which is the remaining gap, but everything needed to invoke correctly is present.

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 100%, so baseline would be 3, but the description adds genuine meaning beyond the enum: it maps each script_type to its directory (powers/, scripts/, npc_scripts/, behaviors/, pet_behaviors/, enchantments/) and the fmm:pet/<file> id form. Minor duplication of the enum list, but the error-consequence framing is added value.

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 (validate) and resource (draft Lua script against the local Nightbreak Forge validator), and its timing/purpose (before finalizing generated Lua files). It is clearly distinguishable from the sibling validate_config_files, which targets configs rather than Lua scripts.

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?

Explicitly says when to use it ('before finalizing generated Lua files') and what it catches (unknown helpers, invalid fields, malformed structure). It does not name sibling alternatives like validate_config_files, so it stops short of full when-not routing, but the usage context is unambiguous.

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