Plant: Cable Takeoff

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

The description discloses extensive behavior beyond the safety annotations: power is never invented, panel inference flags `panel_inferred`, length is Manhattan distance with rounding, totals count power once per package, open items are listed, and refusals occur for invalid lang/allowance/section rules or unreadable drawings. It also explains the write side-effect (XLSX/CSV output) and the fallback when openpyxl is missing. This is far richer than the readOnlyHint=false / destructiveHint=false annotations.

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 front-loaded with a one-sentence purpose, then proceeds through rules, outputs, and refusals in a logical order. It is dense, but each sentence conveys a distinct rule or constraint. There is minor repetition around section rules and open items, but overall it is appropriately sized for a complex 7-parameter tool.

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 an output schema present, the description need not explain return values. It covers prerequisites, defaults, validation refusals, output artifacts, and fallback behavior comprehensively. An agent has everything needed to invoke the tool correctly, including the read-only-on-drawings clarification against the write side-effect.

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 100%, so the baseline is 3. The description adds meaningful parameter constraints beyond the schema: `lang` values outside tr/en/ru are refused, `allowance` outside 0-1 is refused, malformed `section_rules` are named by path, and `output` writes four named sheets plus CSVs. These details go beyond the schema's own parameter descriptions, though some panel_rule behavior is repeated from the 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 first sentence names a specific verb and scope: 'A cable takeoff: one row per electrical load, the shop's cable method made repeatable.' It clearly distinguishes this from generic extraction tools by focusing on electrical loads and a repeatable cable method. An agent can tell it apart from siblings like pipe_takeoff without opening the schema.

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 implies usage by describing the inputs it reads (P&ID, layout) and the output it produces, but it never explicitly states when to choose this tool over alternatives such as pipe_takeoff. No exclusions or 'when not to use' guidance are given. The context is clear enough to infer the tool's purpose, but routing guidance is absent.

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