Compare States

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

The description adds rich behavioral context beyond annotations: it mentions 'full unified diffs', the summary option for faster results, and the capability to search across checkpoints. Annotations already indicate readOnly and idempotent, and the description does not contradict these. It fully informs the agent of safe, stateless behavior.

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 extremely concise: two sentences that front-load the overall purpose and then enumerate specific capabilities without redundancy. Every word serves a purpose, and the structure is clear and easy to parse.

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 tool's complexity (multiple operations, 5 parameters, no output schema), the description covers the core functionality well, explaining key parameter interactions and use cases. It does not detail return format or error handling, but enough context is provided for effective 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?

Schema description coverage is 100%, baseline is 3. The description enhances parameter understanding with usage hints: e.g., name can be '*' for scanning, search requires name='*' and file, against enables cross-checkpoint comparison. This adds meaningful context beyond the schema's brief 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 specifies the tool's purpose: to search and investigate previous versions of the codebase by comparing checkpoints or retrieving file contents. It distinguishes itself from sibling tools like vigil_delete, vigil_list, vigil_restore, and vigil_save through its focus on diffing and historical retrieval.

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 explicit usage scenarios: comparing checkpoints, retrieving file contents, and searching across checkpoints. It mentions parameter interactions (e.g., '*' with file+search for scanning all checkpoints). It lacks explicit when-not-to-use guidance but sufficiently implies that this tool is for investigation, not deletion or saving.

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