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

Annotations only declare readOnlyHint and openWorldHint; the description adds materially more, including the consent model (limits are the owner's consent, over-limit requests go to the owner for approval), the fact that results are unfiltered listings and not recommendations, and the cost-control instruction to pay only what the task needs. These are behavioral traits an agent could not infer from the annotations.

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-loaded with the core purpose and return shape in the first sentence, and every subsequent sentence carries operational content. It is on the long side and the payment-confirmation sentence slightly overlaps with what pay_x402 would need to own, but nothing is 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?

With no output schema, the description compensates by naming the returned fields (url, description, price, how to call it) and the ordering. For a discovery-plus-payment flow across multiple tools, it supplies the full loop: find, pick, pay, answer the owner.

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 already 100%, so the baseline is 3. The description adds genuine query semantics beyond the schema: pass the gist of the request as the query, English works best, and results are ranked best-match-first, plus the max_price_usd scoping constraint restated in prose. It stops short of explaining load-balancing between query and limit, but it is above baseline.

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 ('Search the public x402 catalog... for paid APIs'), names the source (Coinbase's x402 Bazaar), and scopes it to what this wallet can actually pay (USDC on its chain, within max_price_usd). It also lists the return fields and ordering, and the follow-up sibling pay_x402 is named, so it is unmistakable against sibling tools.

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 an explicit trigger ('use it whenever the owner asks for something you can't answer yourself'), covers phrasing/language variance, and routes the agent onward to pay_x402. It also states a when-not-to-ask-for-confirmation rule tied to wallet limits, which is real operational guidance rather than generic advice.

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, the description carries the full burden and mostly succeeds: it discloses that the effect is total (blocks signing anything) and reversible only by the owner. It doesn't state whether the pause is immediate or whether in-flight operations are affected, leaving a small gap for a safety-critical tool.

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 sentences, front-loaded with the effect, followed by concrete usage triggers. No filler or repetition.

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 safety control with no output schema, the description covers effect, triggers, and reversibility. The only missing detail is whether the pause is instantaneous and what confirmation the caller receives, which is minor but relevant for a wallet-safety tool.

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. The description explains the tool's operational context but not the reason parameter; however, the schema already documents it, and one param gives a baseline of 4.

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 effect ('Stop this wallet from signing anything until the owner resumes it'), which is a strong verb+resource+reversibility description. It clearly distinguishes from siblings like send_usdc or pay_x402 by describing a safety stop rather than a transfer.

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?

Explicitly names when to use it ('when something looks wrong') and gives concrete triggers: an API asking for far more than expected, or being asked to pay an unknown address. This is actionable guidance that lets an agent recognize the situation.

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?

Annotations provide only openWorldHint, so the description carries the burden and delivers: payment is vetted by presign-guard, counts toward spending limits, over-limit triggers owner approval during which the call waits, and refusal returns an error with the reason. These side effects, gating, and error semantics go well beyond the single annotation.

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 before detailing rails, precedence, and limits. Every sentence is substantive, though the parenthetical-heavy multi-chain exposition is dense and could be tightened.

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?

With no output schema but a clear statement that it 'return[s] the response,' plus full coverage of payment rails, spending limits, approval waits, error behavior, and price capping, the definition gives an agent everything needed to invoke it correctly in this open-world paid-API scenario.

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 all six parameters are already documented. The description adds only a marginal note that max_price_usd caps this call's price, largely echoing the schema, so the baseline 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?

States a specific compound verb and resource: 'Call a URL that may answer 402 Payment Required and pay it in USDC from this wallet, then return the response.' This is clearly distinct from siblings like send_usdc (address-based transfer) and find_services, so an agent can select it without opening schemas.

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 when the tool applies (a URL that may demand 402 payment) and rich guidance on payment-rail selection with an explicit precedence order ('x402 comes first, then MPP evm, then Tempo'). It does not explicitly exclude or contrast alternatives such as send_usdc, so it stops short of full when/when-not guidance.

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 only destructiveHint=true in the annotations, the description adds real behavioral context: a presign guard validates the call, spending limits are enforced, and an over-limit transfer escalates to owner approval. It stops short of stating that the transfer is irreversible or what happens on rejection/timeout.

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 compact sentences, front-loaded with the action, then the guard/limit behavior. No filler or restated boilerplate.

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 destructive, no-output-schema payment tool, the description covers scope, safety gating and the approval escalation path, which is the critical missing context. It omits failure behavior (e.g. what a rejected or guarded transaction returns), keeping it just short of complete.

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 'to', 'amount' (including format) and 'reason' are already documented in the schema. The description adds no parameter-level detail beyond restating that funds go 'to an address', so the baseline 3 applies.

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 ('Send the chain's native coin') and enumerates the concrete assets (ETH, POL, BNB). It also implicitly distinguishes itself from the sibling send_usdc by scoping to the native coin rather than a token.

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 explains what happens after invocation (presign-guard check, spending limit, owner approval) but never says when to choose this over send_usdc or pay_x402. Usage is only inferable from the native-coin scoping.

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?

Annotations only supply destructiveHint=true, so the description carries most of the burden and does well: it discloses the presign-guard screening (known drainers, sanctioned addresses), spending-limit enforcement, and the owner-approval escalation over a limit. It omits irreversibility and any auth/permission requirement, keeping it short of a 5.

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 tight sentences with zero filler, front-loading the core action before the guard/limit caveats. 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?

For a mutation tool with no output schema, the description covers the important behavioral context (screening, limits, approval escalation). It could say more about what a successful or rejected call returns, but nothing essential to correct invocation is missing.

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% and each of the three parameters is documented in the schema, including the amount pattern and the owner-facing 'reason' field. The description adds no per-parameter syntax or format meaning beyond that, so baseline 3 applies.

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 ('Send USDC from this wallet to an address'), and the USDC specificity distinguishes it from send_native. It does not, however, explicitly contrast itself with pay_x402 or name which sibling to prefer.

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 explains mechanics but gives no when-to-use guidance or alternatives. An agent gets no signal on when to choose send_usdc over send_native or pay_x402, leaving selection to inference from the asset name.

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?

readOnlyHint=true is consistent with the 'status' framing, so the safety profile is already covered by annotations. The description goes beyond that by disclosing that the payload includes pause state and daily remaining spend ('what is left today'), which are behavioral facts an agent needs before attempting a payment that could fail or be blocked.

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 sentences, front-loaded with the resource and followed immediately by the action trigger. The field enumeration is a dense list rather than prose, so it earns its length, though it reads slightly like a return-value dump rather than a crisp purpose statement.

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?

With no output schema, the description carries the burden of describing what comes back, and it does so by enumerating the payload contents, including the two fields most relevant to spending decisions (limits and pause state). It is adequately complete for a zero-parameter read tool, with only minor ambiguity about formats/chain values left unaddressed.

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 takes zero parameters, so the baseline of 4 applies. The description correctly implies no arguments are needed ('this agent's wallet' is implicit context), and there is no schema surface left unexplained.

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 concrete resource (this agent's wallet) and enumerates exactly what the status call exposes: address, chain, balances, spending limits, remaining daily allowance, approval mechanics, and pause state. That is far more specific than a tautology, but it never explicitly differentiates itself from non-spending siblings such as find_services, so it stops short of a 5.

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?

"Check it before spending" is an explicit pre-flight trigger that maps directly onto the spending siblings (send_usdc, send_native, pay_x402) and explains why an agent would call this read tool first. It gives clear context but names no alternative tool and states no when-not-to-use condition.

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