Cross-Rail Settlement Binder

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

With no annotations, the description carries the burden. It discloses that exactly one leaf is appended, restricts leaf types, and includes 'Free' as a behavioral/cost note. However, it does not mention idempotency, failure modes, permissions, or whether appending has any side effects beyond adding the leaf.

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?

Two short sentences with no filler. The action is front-loaded, followed by the leaf-type constraint and the cost note. Every word contributes meaningful information.

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?

The output schema presumably covers return values, so that is not needed in the description. Still, the leaf object structure and the relationship to binder_seal/binder_verify are only implicit, and the 'Free' note is ambiguous. The description gives enough to attempt a call but not enough for confident, correct construction of the nested leaf object.

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 0%, so the description must compensate. It gives task_id meaning as the owning context and constrains leaf to a settlement leaf of type x402, stripe_mpp, or agentcore. However, it does not explain how to represent those types inside the leaf object or what other fields the leaf should contain, leaving a notable gap for a nested arbitrary object.

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 names a specific action (append), a concrete resource (settlement leaf), enumerates the allowed leaf types, and ties the operation to task_id. This clearly differentiates it from the sibling tools binder_seal and binder_verify, whose verbs indicate different lifecycle stages.

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 'under your task_id' provides clear context and a prerequisite for using the tool. While the description does not explicitly name alternatives or exclusion conditions, the append action implies the right lifecycle phase relative to sealing and verifying.

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

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

With no annotations available, the description carries the full burden. It usefully discloses the cost (~$0.05 USDC on Base when paid), the minimum rail count, and the cryptographic output format. However, it does not mention side effects on existing rails, idempotency, or whether the operation is reversible.

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 entire description is a single front-loaded sentence with no filler. It packs the action, the precondition, the output type, and the cost into compact space, and every clause 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?

The description provides enough for basic selection and invocation: required task_id, the ≥2 rails precondition, the output type, and the cost. But it leaves gaps around x402_proof mechanics, the payment flow, and how sealing relates to the sibling operations. These gaps are moderate because an output schema exists, which may carry return-value details.

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 0%, so the description must compensate. It gives meaning to task_id as the grouping key for rails, but x402_proof is only hinted at through 'when paid' and is never explicitly connected to the payment/proof parameter. The agent still lacks clear semantics for the proof field.

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 states a specific action ('Seal'), the resource ('≥2 distinct rails under task_id'), and the output ('portable Ed25519 binder'). It clearly distinguishes this from its siblings by implying finalization rather than appending or verifying.

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 the main precondition: at least two distinct rails must exist under the task_id before sealing. However, it does not explicitly mention when to use binder_seal versus binder_append or binder_verify, or when sealing should be avoided.

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

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

No annotations are provided, so the description carries the behavioral disclosure burden. It discloses what is checked (signature and ordered leaf hashes) and, importantly, what is not checked (underlying settlement), which is a non-obvious and valuable boundary. It does not explicitly state read-only behavior or side effects, but 'verify' strongly implies a non-mutating check.

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 extremely compact: a front-loaded action, a parenthetical technical detail, and a caveat. There is no filler or repetition, and every clause adds distinct information.

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?

The tool has a clear purpose and an important limitation, and an output schema exists to describe return values. However, with no annotations and a schema that provides no structure for 'binder', the description does not fully explain how to populate or pass the input. It also does not mention when to prefer it over, or avoid it in favor of, other tools beyond the settlement caveat.

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 only parameter, 'binder', is an opaque object with additionalProperties true and zero schema descriptions. The description partially compensates by naming the components that matter ('sig + ordered leaf hashes'), but it does not define the expected shape, field names, or how the binder should be obtained or constructed. The compensation is therefore only partial.

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 uses a specific verb 'Verify' with a clear resource, 'binder integrity', and expands on what that means: 'sig + ordered leaf hashes'. The negative clause 'Does not prove underlying settlement' further sharpens the boundary. This clearly distinguishes the tool from mutating siblings like binder_append and binder_seal.

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 for when to use the tool: when binder integrity needs to be checked. It also provides an explicit limitation, 'Does not prove underlying settlement', warning the agent not to treat this as a settlement proof. It stops short of naming specific alternative tools or conditions, so it does not fully earn a 5.

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

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It hints at a read-only status report via 'Liveness' but never confirms absence of side effects, cost, or auth requirements. The description discloses only return content, not behavior.

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 a seven-word fragment with zero wasted words, which is efficient. However, the brevity crosses into under-specification, sacrificing a complete sentence for a compressed label.

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?

Complexity is low (0 parameters) and an output schema exists, which lowers the bar for what the description must cover. Still, with no annotations, the description alone must establish the tool's role, and a seven-word fragment is only minimally adequate for that.

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 tool has zero parameters, so the rubric baseline of 4 applies. With no input schema properties, there is nothing the description needs to clarify about argument semantics, and nothing is missing on that front.

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 is a telegraphic noun-phrase list ('Liveness, rails, pubkey, paid/listing flags') rather than a statement of what the tool does. The word 'Liveness' plus the tool name 'health' make a status/health check inferable, but no verb is present and the intended operation is never explicitly claimed. It avoids tautology by adding content beyond the name, but the purpose remains vague.

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 offers no guidance on when to call this tool or when to prefer a sibling. Differentiation from binder_append/binder_seal/binder_verify rests entirely on name semantics; the description never states 'use this to check service status' or names any alternatives or exclusions.

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