place_fb_in_ladder

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

Since no annotations are provided, the description must carry the full behavioral burden. It discloses key internal behavior: reads the DFB's pin interface, places the block with computed height (max(in,out)+1), wires one boolean input to the rail, and auto-declares bindings with the right types. This gives significant insight into what the tool does beyond the schema, enough to predict side effects like variable creation.

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 well-structured: a clear purpose in the first sentence, a rationale paragraph, then per-parameter explanations, followed by usage notes. Each sentence adds value; there is no fluff. It is somewhat long but appropriate for the tool's complexity. The key information is front-loaded, and the parameter list is organized with examples.

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?

For a tool of this complexity (8 parameters, no output schema, no annotations), the description covers the main mechanics and defaults, but leaves important gaps. The 'section' parameter is required yet unexplained, and 'task' and 'pos_x' are only mentioned by default values. It also doesn't describe return values or error scenarios. The description is sufficient for a rough understanding but not fully complete for correct invocation without additional inference.

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 0%, so the description must document all parameters. It explains fb_type, instance_name, bindings, rung_input, and rung_contact with examples, covering 5 of 8 parameters. However, it omits explanations for section (required), task, and pos_x, leaving them ambiguous. The agent has to infer their meaning from names and defaults, which is insufficient given the lack of schema descriptions.

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 starts with a clear, specific verb and resource: 'Place a function block in LADDER from scratch'. It explicitly differentiates from alternative authoring by stating 'NO template needed' and 'For elementary EFBs (TON/CTU/…) author in FBD instead', which implies this tool is for project DFBs. This gives the agent a precise understanding of what the tool does and how it differs from related tools.

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 when-not-to-use guidance: 'For elementary EFBs (TON/CTU/…) author in FBD instead.' It also says 'Then build_project to confirm,' indicating a follow-up step. However, it doesn't explicitly compare with the sibling 'use_fb_in_ladder', though the 'from scratch — NO template needed' phrase implicitly contrasts it. This is clear enough for an agent to decide when to invoke this tool.

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