Plecs Compare

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

readOnlyHint already declares the safety profile, so the description's added value is the output shape: raw MergedItem lines plus parsed entries with depth/left/right/change/type. That is genuinely useful context, but it doesn't cover failure modes (missing files, unparseable models) or size limits of the diff.

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?

Two compact sentences that front-load the action and then the result format; nothing is padded. The Markdown-style double-backtick fragments are slightly noisy but not costly.

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 needn't be spelled out here, and the read-only nature is covered by annotations. The remaining gap is path semantics for the two required inputs, which neither the schema nor the description explains for a tool whose correctness depends on them.

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 two required parameters (before_path, after_path) carry no documented meaning beyond their names. The description doesn't clarify that these are model file paths, whether relative or absolute, or which one is the baseline in the diff direction.

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?

States a specific verb and resource ("Compare two model files") plus the underlying engine, which no sibling tool offers. An agent can identify this as the diff tool without consulting another definition, though it doesn't explicitly contrast with nearby read-only tools like plecs_get or plecs_overview.

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 never says when to reach for this tool versus alternatives (e.g., inspecting a model via plecs_get_model_tree or validating via plecs_check). No preconditions such as both files needing to exist or be loadable are mentioned.

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