compare_versions

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

With no annotations provided, the description carries the full transparency burden. It explicitly discloses behaviors: 'Loads and fits both .inp files', returns a comparison figure, mentions the nested LR test condition, and notes that guion_path is 'unused currently, reserved'. This adds significant context beyond the schema, though it does not explicitly state whether any files are modified or side effects occur.

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 and front-loaded. The first line states the purpose, followed by a clear bulleted list of return items and a compact parameter table. Every sentence contributes meaningful information, and the 'reserved' note avoids confusion. No unnecessary verbosity.

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?

The tool is complex (compares two models with multiple outputs), and no output schema exists, so the description appropriately explains return values and parameter semantics. It covers the main functionality, including the conditional LR test and figure generation. However, it does not mention potential error conditions (e.g., invalid .inp files) or prerequisites beyond fitting the files, so it is not fully complete.

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 compensate. It includes a detailed Parameters section explaining each parameter: inp_path_a, inp_path_b, lam_a, lam_b, guion_path, with meanings and defaults (e.g., 'lam_a: Box-Cox lambda for model A (0.0 = log)'). This fully compensates for the schema's lack of 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 function: 'Compare two estimated models' with specific outputs (spec diff, stats table, nested LR test). It identifies the specific resources (.inp files) and scope, which distinguishes it from sibling tools like estimate_and_diagnose or model_histogram.

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 stating 'Compare two estimated models' and listing the return items, but it does not explicitly say when to use this tool versus alternatives (e.g., record_version or estimate_and_diagnose). It provides context but lacks explicit exclusions or alternative references.

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