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

Annotations already declare the mutation profile (readOnlyHint=false, idempotentHint=true, destructiveHint=false), and the description adds real value on top: the target-resolution chain (argument → x-mp-game header → only game) and the explicit refusal behavior on ambiguity. It doesn't say whether an existing name is overwritten, though idempotentHint implies repeat calls are safe.

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 sentences, front-loaded with the action and followed by rationale and edge-case behavior. Minor redundancy with the schema's `game` description, but nothing extraneous.

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 tool with full schema coverage and annotations, the description covers purpose, trigger, targeting precedence, and the ambiguous-studio failure mode. With no output schema there is no return-value burden left unmet.

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% and the schema already documents both the `game` fallback chain and the `name` format, so the description's restatement of the resolution order is reinforcement rather than new meaning. Baseline 3 is appropriate when the schema does the heavy lifting.

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 ('Set a human-readable name for a game') and immediately clarifies what the name affects ('shows in your dashboard'). It is clearly distinct from siblings like create_game or list_games, which handle game lifecycle rather than naming.

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?

'Call this when you start building so the game isn't unnamed' gives an explicit trigger for use, and 'Refuses to guess when the studio has several games and none was named' describes the failure condition. It doesn't mention create_game as an alternative place to set a name, but the usage context is otherwise clear.

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