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

Annotations already flag destructiveHint=true, so the description's real contribution is the extras: the call is free, the ops are applied as a batch 'in one step', and a 409 returns the new revision with the ops explicitly NOT re-applied. That last point is the key non-obvious behavior and prevents a retry storm. It stops short of saying whether a failure mid-batch leaves partial state or what happens when ops target nonexistent lines.

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 front-loaded with the action and cost note, then cleanly split into Args and Returns blocks that map one-to-one onto the schema and response shape. Every line contributes: the examples, the count bound, the conflict semantics, and the return contract. No filler.

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 destructive batch-mutation tool with no output schema, the description does the important work of documenting the return shape and the revision-conflict outcome inline. What it leaves unresolved is the op catalogue (the schema permits arbitrary extra fields per op) and batch failure semantics, which are the two things an agent most needs before composing a 50-op payload.

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 coverage is only 33%, with project_id as the sole documented parameter, so the description must carry the rest — and it partly does, giving ops cardinality (1-50) and per-item shape ({op, ...fields}) plus if_revision as 'the revision you read'. The critical gap is the op vocabulary: the item schema only constrains op by a name pattern and allows additionalProperties, so the '...' in the example list leaves the agent without a reliable catalogue of valid op names and their fields.

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 names a concrete action and resource: 'Apply editor ops (set_line, split, merge, set_setting, bind_visual, ...) in one step' to a Studio project. It even enumerates representative ops, so the agent knows the shape of the work. It does not distinguish itself from the sibling studio_edit, so the agent cannot tell from this text alone which patch-style vs edit-style tool to pick.

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?

Usage is implied by the concurrency protocol: if_revision must match what was read, and a 409 means the project moved on. That tells the agent when the call will succeed or fail, but there is no explicit statement of when to prefer this tool over studio_edit or the other studio_* siblings, and no stated prerequisites such as required permissions.

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