ads_app_info

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds the field inventory, which is useful, but says nothing about connection/auth requirements or whether it is safe to poll repeatedly. Adequate with annotations, but not rich.

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?

A single dense sentence with the resource definition front-loaded and the field list appended parenthetically. It earns its place, though the internal TwinCAT type name is borderline clutter for an agent.

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?

With no parameters and an output schema present, the description needn't explain return formatting, and it does supply the semantic meaning of the payload fields. The only real gap is the lack of connection/precondition context for a PLC-targeted read.

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?

The tool takes zero parameters, so the baseline is 4. The empty schema leaves nothing to disambiguate, and the description correctly adds no parameter guidance that would be redundant.

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?

Names the specific resource (PLC application info, anchored to TwinCAT_SystemInfoVarList._AppInfo) and enumerates the fields it covers, so an agent knows exactly what it returns. It does not differentiate itself from adjacent siblings such as ads_status or ads_task_stats, which overlap on task count and state, so it falls short of a 5.

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?

There is no when-to-use guidance, no stated prerequisites (e.g. an active ADS connection via ads_connect), and no named alternative among the many ads_* siblings. The agent must infer invocation context entirely.

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