plc_library

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

With no annotations provided, the description carries the full burden. It discloses that READ has no side effects, WRITE involves offline .plcproj edits with no runtime impact, and REPO ADMIN mutates machine-wide state. It also notes the LANDMINE about solution close/reopen and that repo admin is guarded with confirm. It does not cover error handling or concurrency, but the coverage is substantial.

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 long but well-structured with clear sections (READ, WRITE, LANDMINE, REPO ADMIN). It is front-loaded with the core purpose. Every sentence adds useful information, though it is dense and could be slightly trimmed without losing clarity.

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?

Given the tool's complexity (20 parameters, many actions) and no output schema, the description covers the main actions, their effects, and key caveats. It provides partial output structure for READ actions (e.g., 'list → name/kind/displayName/...') but lacks details for WRITE and REPO ADMIN return values. Overall, it is fairly complete for an agent to understand usage.

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 description coverage is only 15%, so the description must compensate. It explains the action enum values in detail, and for each action it lists relevant parameters (e.g., add_library takes name, version?, company?). However, several parameters (lib, dist, mode, index, confirm, etc.) are not explained or only partially covered. The description adds value but is not comprehensive.

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 clearly states the tool manages PLC library references, placeholders, and repositories via ITcPlcLibraryManager. It lists specific actions (list, scan, repos, add_library, etc.) and their effects. It distinguishes itself from sibling tools by focusing on library management, not build, download, or other TwinCAT operations.

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 provides explicit guidance on when to use each action, including READ vs WRITE distinctions, and the LANDMINE about needing solution close/reopen for certain edits. It also mentions the confirm parameter requirement for repo admin. However, it does not explicitly state when NOT to use this tool or compare to alternatives.

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