sketch_mirror

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

With no annotations, the description carries the burden and does meaningful work: it discloses atomicity ("all or nothing"), resulting topology behavior (shared points stay shared, axis points reused), and the failure mode with a named error code. It leaves gaps around what happens to the source entities and whether the operation requires an active sketch edit session, but the mutation semantics are far better covered than typical.

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?

Front-loaded with the action and its atomicity clause, followed by behavior, return shape, and a compact example — every sentence earns its place. It is slightly denser than strictly necessary (the example largely restates the schema) but not wasteful.

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 5-parameter mutation tool with no annotations and no output schema, the definition covers the return shape inline (mapping, constraints, status, profiles), the error contract, and atomicity — the essentials an agent needs before calling. Remaining gaps are the source-entity outcome and whether an edit session is required.

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%, so the schema already documents all five parameters, including the constrain and return_profiles defaults. The description adds value only through the worked example mapping sketch/entities/axis to real argument shapes, and says nothing about the two optional flags.

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 leads with a specific verb+resource pair ("Mirror entities about a line") scoped to sketch entities, which an agent can distinguish from feature-level siblings like pattern_mirror or feature_mirror-ish tools by the entities/axis arguments. It does not explicitly name the nearest alternative (sketch_pattern), so it stops short of full sibling differentiation.

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 gives real operating context: the operation is all-or-nothing, and unsupported curve types fail with INVALID_PARAMS, which tells the agent what inputs are valid. However, there is no explicit when-to-use guidance versus sketch_pattern or pattern_mirror, and no stated prerequisites (e.g., active document, edit context).

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