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

Beyond the annotations, it discloses the write prerequisite (editToken), the concurrency requirement (latest revision), the return contract (new revision), and the non-overwrite guarantee. This is strong behavioral context for a mutation tool and aligns with readOnlyHint=false and destructiveHint=false.

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 short sentences front-load the core action, then cover prerequisites and the non-overwrite guarantee with no filler. Every sentence carries operational weight.

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 complex nested-object tool, the description gives the essential high-level contract: one insertion, required capabilities, returned revision, and uniqueness. The rich input schema covers the shape/connector details and points to get_drawing_format, so no critical operational context is missing.

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 100%, so the schema already documents every parameter; the description adds actionable guidance on shape.id (must be new/unique) and stresses that revision must be the latest. This goes slightly beyond the schema's baseline, though it leaves afterId ordering to the schema.

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 first sentence states a specific verb ('Insert'), a concrete resource ('an existing drawing'), and a strict cardinality ('exactly one object'), so an agent knows this is the add-not-create, add-not-update tool. The unique-id guarantee further distinguishes it from update_shape and remove_shape.

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 clearly frames the use case: adding one new shape to a drawing that already exists, with a fresh shape.id and the latest revision. It does not explicitly name sibling alternatives like update_shape or remove_shape, but the new-id/no-overwrite constraint implies when not to use it.

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