add-rule-to-mode

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

No annotations are provided, so the description carries the full burden. It discloses useful behaviors: places rule in correct mode, validates mode exists, supports all lexer rule options, and auto-sorts within the mode. It also shows example usages with action. It does not mention potential error behavior or return format, but the key behavioral traits are covered.

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 with a clear opening statement, a 'When to use' section, a bulleted feature list, and two illustrative examples. It is not overly verbose, and the front-loaded purpose makes it easy to grasp quickly. The examples add useful detail but could be seen as slightly redundant.

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 the complexity of the tool (11 parameters, no annotations, no output schema), the description does a good job of covering the essential usage context. It explains what the tool does, when to use it, and provides examples. It doesn't fully explain edge cases like the relationship between from_file and grammar_content, or the meaning of output_mode, but the schema covers these and the description is reasonably complete for practical use.

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?

The input schema already provides 100% coverage of parameter descriptions, so the baseline is 3. The description adds value by providing concrete examples that show how rule_name, pattern, mode_name, action, and write_to_file are used together. This clarifies the intended semantics beyond individual 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 clearly states the tool's purpose: 'Add a lexer rule to a specific mode in an ANTLR4 grammar.' It uses a specific verb (add) and resource (lexer rule to a mode), and this distinguishes it from siblings like add-rule (general) and move-rule-to-mode (moving existing rules).

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 a 'When to use' section: 'Adding tokens that only apply in specific lexical contexts.' This gives clear guidance on when this tool is appropriate, and the examples illustrate usage. It doesn't explicitly state when not to use it or mention alternatives, but the context strongly implies it's for mode-specific rules rather than global rules.

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