browser_inject_signer

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

With no annotations provided, the description must carry the full burden. It fails to mention side effects like replacing window.ethereum, the impact on existing providers, whether the injection is persistent, or the security implications of using a private key. It only states the injection action and its MetaMask independence.

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 description is two short sentences with no wasted words, front-loading the central action. It is easily scanned, though it lacks structural depth; however, conciseness itself is good.

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?

Despite having an output schema, the description omits critical context for a tool that handles a private key. It doesn't explain what the tool returns, whether it activates the provider, or how to undo the injection. No annotations compensate, leaving a significant 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 baseline is 3. The description adds no additional parameter meaning beyond the schema's own descriptions of slot, chain_id, and private_key. It does not explain how these parameters affect the injected provider.

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 clearly states the tool's function with a specific verb ('inject') and resource ('minimal EIP-1193 wallet provider'). The phrase 'No MetaMask needed' differentiates it from relying on MetaMask and, combined with the name, distinguishes it from the sibling 'browser_inject_passkey'.

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?

No explicit guidance on when to use the tool versus alternatives such as browser_inject_passkey or simply using MetaMask. The 'No MetaMask needed' line implies a use case but doesn't state prerequisites, exclusions, or scenarios where this tool should be preferred.

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