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

With no annotations supplied, the description carries the full burden and does so thoroughly: unproven assertion semantics, that changing the address clears prior verification, that only future deposits match, that detaching leaves balances untouched, and that 1 CRD is charged even on rejection except for 429 RATE_LIMITED. The error/request_id guidance is exactly the kind of operational detail an agent needs.

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-loads the core action, then layers semantics, edge cases, cost, and error handling in descending priority. Every sentence contributes a distinct fact; there is no restatement of the name or filler.

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 6-parameter mutation with no annotations and no output schema, this covers nearly everything an agent needs: cost model, rejection behavior, verification invalidation, and detach semantics. The only gap is the success response shape and how the user is resolved when multiple identifiers are supplied.

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 coverage is 100%, so the baseline is 3, but the description adds real meaning: wallet_address=null detaches and balances are unaffected, and the per-call CRD cost contextualizes the x402_payment escape hatch. It does not clarify the precedence among user_email/external_id (only the schema notes 'checked first'), leaving that to structured data.

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 ("Attach an EVM address to an end user") plus the downstream effect (on-chain credits mint to them). The clause "No signature required" implicitly separates it from the verify_wallet_signature / request_wallet_challenge siblings without the agent needing to open another schema.

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?

Gives clear context for use (so on-chain credits mint to the user) and a distinct non-use case (the assertion path versus the signature-proof path), plus the detach case via null. It stops short of naming the sibling tools explicitly, so the agent must infer the alternatives from the 'no signature' contrast.

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