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

Despite annotations already flagging a destructive mutation, the description adds substantial behavioral detail the annotations cannot convey: the old id keeps working and its commons dedication stands, only the listing moves; a supersededBy edge is written; re-pointing preserves the earlier edge; edges carry no timestamps so the current successor is the returned `current` record; and taxonomic edges are offered for migration, never moved.

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 purpose is front-loaded in the first sentence and every sentence carries real information. It is dense and the edge-ordering sentence is somewhat convoluted, but there is little outright waste for a tool with this much behavior to disclose.

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 mutation tool with no output schema, the description covers the mutation's effect, ownership requirements, edge side effects, the return value (the `current` supersededBy record), and how related edge migration works. Nothing an agent needs to invoke it correctly 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% and both parameters are documented in the schema, so the baseline is 3. The description adds meaning beyond that by clarifying the ownership constraint ('Both models must be yours') and the semantic role of each id (old keeps working, new is the successor), which the schema alone doesn't state.

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: 'Mark an old version of your model as replaced by a newer one.' It is immediately distinguishable from siblings like sim_delete_model, sim_create_model, and sim_accept_migration because it defines the supersession relationship rather than deletion or creation.

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 gives clear preconditions ('Both models must be yours') and routes related operations to siblings: sim_migration_offers and sim_accept_migration for taxonomic edges, sim_edges/sim_neighbors for inspecting the recorded edge. It doesn't explicitly say when to choose this over an alternative, but the context is strong.

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