plc_read_section

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuine context beyond that: the call may return either textual source or native Ladder representation, and it can operate against staged transaction state rather than committed data. It does not say whether the caller must own or hold the transaction, which is the main behavioral ambiguity for a transaction-aware read.

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 front-loaded sentence with no filler or repetition. It is efficient, though its terseness leaves the transaction-state clause doing more work than its wording supports.

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?

An output schema exists, so return values need not be described, and the annotations cover the safety characteristics. Still, for a 5-parameter read with 40% schema coverage and a transaction-related behavior, the description should clarify what transaction_id does and how the source-versus-Ladder output is determined; those gaps matter for correct invocation.

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 40%, so the description needs to compensate, and it only does so for one parameter by implying that transaction_id switches to staged state. project_id, section_id, and the mechanics of choosing between source lines and Ladder rungs are not explained, and notably no visible parameter appears to select that output flavor, which the description leaves unresolved.

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 gives a specific verb ("Read") tied to a concrete resource ("source lines or native Ladder rungs") of a section, so an agent knows it retrieves section content rather than metadata. It does not differentiate itself from the sibling plc_read_pou, so the boundary between reading a POU and reading a section is left to inference.

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?

"Optionally from staged transaction state" hints that transaction_id selects a staged view, but it never states when to use that mode versus the committed view, nor when to prefer this tool over plc_read_pou or plc_inspect_file. There are no exclusions or prerequisites, leaving usage almost entirely to inference.

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