td_variant_save

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

With no annotations provided, the description carries the full behavioral burden and does so impressively. It discloses storage location (~/.td-atlas/variants), grouping by project path, the byte-copy component, duplicate-label refusal, and the path parameter's scoping semantics. It even includes performance characteristics (median 19% overhead) and reassures that 'Nothing of the user's is touched.' This goes well beyond basic mutation disclosure.

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 moderately long but every sentence earns its place: front-loaded purpose, usage example, storage/behavior details, and parameter constraints. The structure flows logically from what to why to parameter-specific caveats. There is no filler or repetition that bloats the description.

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 description is complete for the tool's complexity. It covers what, when, how it behaves, where it stores, parameter meanings, and important constraints—all without needing to explain return values because an output schema exists. An agent can call this tool correctly with the given information.

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 does add meaningful semantics for 'label' (allowed characters, duplicate refusal) and 'path' (narrows only the stored text; copy is always whole file). However, it does not explicitly explain 'file' or 'note'. File is implicitly a .toe/.tox path from context, and note is optional, but leaving note entirely unexplained is a minor gap given zero 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 opens with a specific verb and resource: 'Keep the current state of a .toe/.tox so it can be returned to and compared.' This clearly distinguishes it from sibling tools like td_variant_diff and td_variant_restore, which are referenced within the description. It tells the agent exactly what the tool does and why it exists.

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 concrete usage guidance: 'Take one before trying a direction, another after, and td_variant_diff says exactly what the direction changed.' It also states the intent of restore and compare, and names the specific sibling for diffing. It does not explicitly say when not to use it or contrast it with every alternative (e.g., td_snapshot), but the context is clear enough for an agent to select it appropriately.

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