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

Annotations cover only the safety profile (idempotent, non-destructive, not read-only). The description goes well beyond that: it explains the state transition (previous cut marked `superseded` and retained in history, not deleted), the downstream effect (next production run renders the new cut), the write-scope requirement, and the cost ($0). That is exactly the extra context annotations cannot supply.

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?

Three tight clauses, front-loaded with the core verb and resource, then the human-analogue, then the consequences, auth and cost. Nothing is redundant; every clause carries distinct information.

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?

For a two-parameter mutation with no output schema and annotations already declaring idempotency and non-destructiveness, the description supplies the important missing pieces: reversibility semantics, downstream render effect, and auth/cost. The only shortfall is parameter-level detail for project_id, which is a minor gap against an otherwise complete picture.

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?

At 50% schema description coverage, the description must compensate for the undocumented parameter, but it adds no parameter-level detail at all. project_id is neither explained nor qualified (scope, format, where it comes from), and version_id is only loosely implied by 'an existing version'. The schema does at least describe version_id as belonging to the project timeline, so this is not a total void, but the compensation the coverage gap calls for is absent.

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?

States a specific verb and resource — 'Makes an existing version THE CUT the production line renders' — and disambiguates it from neighbouring tools by naming the concrete state it sets (the rendered head), not a vague 'update'. An agent can distinguish this from produce, list_versions, or commit without opening the schema.

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?

It anchors the operation to a familiar human action ('the same act as the human's «restore» on the version timeline'), which tells the agent when this is the right tool. It also states the 'Requires `write`' precondition and $0 cost. It stops short of naming an explicit alternative or exclusion, so it is clear context rather than full routing guidance.

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