register_input_key_mapping

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

Annotations declare readOnly=false, destructive=false, idempotent=false, but the description adds real value beyond them: it explains the call can be refused by the engine and that refusal reasons come back in failure_tags, and it sketches the return payload. That failure-mode disclosure is exactly the kind of context annotations cannot carry.

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 operation, then the engine wrapper, then the failure mode, then the return shape. Three sentences plus a returns line, with no filler. Slightly more verbose than necessary given nothing is wasted.

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?

No output schema exists, so the inline Returns block meaningfully fills the gap. With 100% schema coverage on inputs and failure_tags behavior explained, an agent has what it needs to call the tool, though the absence of any sibling routing is a residual gap.

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 slot enum values and key-name format. The description only names 'mapping name + new key + slot' without adding syntax or constraint detail, so the baseline 3 applies.

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: 'Remaps a player input mapping to a new key at runtime,' and names the underlying engine entry point. It is clear what the tool does, but it never distinguishes itself from adjacent input tools (map_input_action, add_mapping_to_context, unregister_input_key_mapping), leaving sibling disambiguation to the agent.

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 phrase 'at runtime' hints at context, but there is no explicit when-to-use, when-not-to-use, or named alternative. An agent cannot tell from this text why it would pick this tool over map_input_action for the same mapping.

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