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

With no annotations, the description carries the full burden and does excellently. It discloses authentication via bearer token, a per-call payment option with specific instructions, and the on-chain immutability of signals ('sealed on chain... cannot be edited afterward'). It also notes that anyone can verify with free proof tools.

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 efficient and every sentence adds value, but it front-loads the payment/auth requirement before stating the core purpose. A more purpose-first structure would improve scannability, though this is a minor issue.

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?

Given the tool's simplicity, an output schema, and two optional parameters, the description covers auth, cost, content, immutability, verification, and parameter limits. It doesn't explicitly state read-only behavior or rate limits, but these are reasonably implied by the context and the absence of side effects.

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 has 0% description coverage, so the description compensates by noting both parameters are optional, that 'chain' filters the stream, and that 'limit' is capped at 50. While it doesn't explain each enum value, the schema already lists the enums, and the description adds crucial bounds and optionality.

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 returns 'The live ChainHelix signal stream, newest first,' and details the signal content (chain, direction, entry price, win probability, conviction score). This distinguishes it from siblings like prices or market_state.

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 context: it is a live stream, newest first, with optional chain and limit parameters. It also mentions 'free proof tools' as an alternative for verification, but does not explicitly say when to use this tool versus other signal-related siblings, leaving a small gap.

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