apply_weight_edits

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

Annotations only say it is non-read-only and not open-world; the description goes much further by disclosing that the source is preserved, that output is a new checkpoint, that all bytes are copied before modification (a cost/time signal), and exactly which conditions cause rejection (stale token, output name collision, invalid shapes, nonfinite results). That is concrete failure-mode and side-effect information the annotations do not carry.

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 action and its prerequisite are front-loaded, and each following sentence adds a distinct fact (preservation, rejections, byte copying). The fragmentary telegraphic style is compact but slightly clipped, and the byte-copy sentence could be folded into the preservation statement.

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 need not be explained, and the description covers the prerequisite, safety profile, and rejection modes adequately for a mutation tool. The single meaningful gap is that the nested edit-request structure, the tool's largest input, is left entirely undocumented.

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 carry the burden. It explains expected_plan_token ('preview's plan_token') and implies the output parameter through the name-collision rule, but says nothing about the required 'request' object (model, edits array, the nine operation types, alpha/value/ranges fields), which is the bulk of the actual input surface.

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?

Specific verb plus resource ('Apply a previewed numerical edit into a new checkpoint') with an explicit scope: the edit must already have been previewed. The reference to 'preview's plan_token' implicitly separates it from the preview_weight_edits sibling, so an agent can tell which of the pair writes and which only plans.

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 prerequisite is stated ('Pass preview's plan_token'), which tells the agent this must follow a preview call, and the name-collision constraint ('existing output names ... rejected') warns that the target must be fresh. It stops short of naming the preview tool explicitly or stating any when-not-to-use case.

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