send_raw_transaction

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

Beyond annotations (readOnly=false, destructiveHint=true), the description discloses that the server never receives a private key, a meaningful security behavior not present in annotations. The phrase 'already-signed' also clarifies that the tool does not sign transactions, adding behavioral context beyond the structured metadata.

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 sentences long, with the primary action front-loaded in the first sentence. The second sentence adds a valuable security guarantee without any unnecessary words. Every part earns its place.

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 single-parameter tool with strong annotations, the description is mostly sufficient. However, there is no output schema and the description does not mention what the tool returns (e.g., transaction hash) or potential error conditions, leaving a small gap in completeness for an agent that might need to confirm the result.

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?

The schema already fully describes the single parameter 'rawTransaction' as '0x-prefixed signed transaction bytes' (100% coverage). The description's mention of 'already-signed' adds no new meaning beyond what the schema provides, so the baseline of 3 is appropriate.

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 action 'Broadcast' and the resource 'raw EVM transaction', distinguishing it from the sibling read-only tools. The added note about never receiving a private key reinforces the tool's unique role as a broadcast-only operation, making its purpose unambiguous.

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 implies a key prerequisite: the transaction must already be signed, since it says 'already-signed'. It also signals that the server is not a signer by noting it never receives a private key. While it doesn't explicitly compare to alternatives, the sibling tools are all read-only, so this is clearly the only broadcast tool; no explicit exclusion is necessary.

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