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

Annotations already establish the safe read-only, non-open-world profile, so the bar is lower. The description still adds real behavioral context: a one-call-per-session contract and a cost signal ('Cheap, no embedding'), which annotations cannot convey.

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 purpose, then usage, then contents, then cost — a sensible information hierarchy. Each clause carries information, though the middle enumeration of covered topics is dense and slightly longer than strictly necessary.

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 must describe what the guide returns, and it does: result modifiers, invokeNative vs invokeNativeByHash, type mapping, pointer gotchas, and worked examples. For a static reference-loading tool this covers everything an agent needs.

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?

Only one parameter, and schema coverage is 100% with an enum that fully documents 'js'/'lua'. The description merely restates the two allowed values, adding no syntax or format detail beyond the schema, so the baseline 3 applies.

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 ('Load') and resource ('calling-convention reference for RedM/RDR3 natives') with the two target languages named. It implicitly differentiates from the native-doc siblings by explaining that this guide exists because 'every native doc page only shows Lua examples,' though it never names a sibling tool explicitly.

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?

Clear when-to-use directive: 'Call ONCE per session before writing native-calling code,' which also encodes an exclusion (do not call it repeatedly). It identifies the audience (JS/TS authors needing translation) but does not name the sibling (lookup_native) as a companion or alternative.

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