Compare API availability across clients

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

With no annotations, the description carries the burden of behavioral disclosure. It clearly states the tool checks existence, implying a read-only query, but it does not detail the return format (e.g., a per-client boolean table) or any error behavior. The description is not misleading but lacks depth beyond the basic operation.

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 two sentences, front-loaded with the purpose, then gives a concrete usage scenario. Every sentence earns its place, and there is no wasted text or redundancy with the schema.

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?

This is a simple single-parameter lookup tool with no output schema. The description covers what it checks, which clients, and when to use it. It omits details about the output structure, but for a 1-param diff tool of this simplicity, the description is sufficiently complete for an agent to select and invoke it.

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%, with the parameter description already explaining 'Function, event or type name, e.g. GetSpellInfo or C_Item.GetItemInfo.' The tool description repeats 'function, event or type' but adds no new meaning about the parameter beyond what the schema provides, so the baseline score of 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?

The description uses a specific verb phrase 'Check whether a function, event or type exists in each game client' and clearly names the resource (function/event/type) and scope (retail, Classic progression, Classic Era). This distinguishes it from sibling search tools like wow_api_search, which find definitions rather than compare availability across clients.

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 gives explicit when-to-use guidance: 'Use this before writing code that has to run on more than one flavor, or to explain why something works on Classic but not retail.' This provides clear context, though it does not explicitly name alternative tools for when not to use it (e.g., 'use wow_api_search to find where something is defined').

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