plc_session

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

With no annotations, the description carries full burden. It discloses that status is read-only, logout logs out and applies source edits, and that logout requires confirmation with a specific value. It also states the tool never logs back in. This is transparent for its simplicity, though it could detail error handling.

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 plus a brief list, front-loading the purpose and then detailing each action. Every sentence adds value; no fluff. Highly efficient.

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 no annotations or output schema, the description covers purpose, both actions, effects, and guards. It mentions status output format and logout side effects. It could be more explicit about the output schema or error cases, but for a simple tool it is largely complete.

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 has 0% coverage, but description adds full meaning: explains the 'action' enum values (status is read-only, logout logs out) and clarifies that 'confirm' is needed only for logout, with exact required value 'ALLOW_PLC_LOGOUT'. This is highly informative beyond schema.

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 is for 'PLC online-session control via UI Automation', with explicit actions (status, logout). It distinguishes itself from siblings by focusing on session management, not downloading, libraries, or other PLC 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 explains that DTE Login/Logout commands are unavailable on 64-bit shell, implying this tool is the substitute. It also warns 'Never logs back in', guiding usage. However, it doesn't name an alternative for logging back in, which slightly limits guidance.

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