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

With no annotations, the description carries the full transparency burden. It explicitly discloses that the tool is offline and does not initiate a request, and it reveals the internal mapping of the product parameter to Alipay trade methods. However, it does not disclose credential requirements, signing behavior, or error handling, so it is not fully transparent.

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 single dense sentence that front-loads the tool's purpose and offline behavior before enumerating the product-to-API mapping. Every phrase earns its place; there is no repetition 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?

The tool has moderate complexity with nested order and cred objects, seven parameters, and no output schema, yet the description says nothing about the return value, how to consume the generated URL, sandbox behavior, or failure cases beyond the product mapping. The offline note helps, but the overall context is too thin for an agent to invoke the tool confidently without further assumptions.

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 only 14%, so the description must compensate. It adds crucial semantics for the product enum by linking each value to a specific Alipay API, and clarifies cred omission via environment variables. But it does not explain order fields (outTradeNo, amountYuan, subject) or URL-related parameters like notifyUrl, returnUrl, quitUrl, and sandbox, leaving a significant portion of the schema 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 the specific verb (生成/generate) and resource (支付宝支付跳转链接/Alipay payment redirect URL), and adds the key qualifier '离线，不发起请求' (offline, no request), which separates it from network-issuing payment tools. It even maps product values to the exact Alipay APIs (page → alipay.trade.page.pay, wap → alipay.trade.wap.pay), making the purpose unmistakable even among sibling Alipay 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?

The description implies when to use the tool: when you need an offline Alipay payment redirect URL. It does not explicitly name alternatives or state when not to use it, such as when an actual Alipay request or order creation is required, so the guidance is present but only implicit.

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 burden of behavioral disclosure. It does disclose the split between dry-run and actual invocation, which is valuable. However, it does not explain side effects of the real call, authentication/credential expectations, error behavior, or reversibility, leaving gaps for a tool that can perform a real external API call.

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 single compact sentence that front-loads the tool's purpose and immediately clarifies the critical execute behavior. Every clause adds useful information and there is no padding or redundancy.

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 moderate complexity with nested objects, no output schema, and no annotations, the description is adequate but not complete. It explains the main modes and the QR code output, but leaves parameter details, authentication fallbacks, and broader behavioral expectations to the schema or agent inference.

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 only 40%, so the description needs to compensate for undocumented parameters. It only adds meaning for the execute parameter; the order object fields, cred, sandbox, and notifyUrl are not explained in the description. Some schema descriptions exist, but the description does not add enough value to cover the low coverage.

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 identifies the tool as Alipay Face-to-Face Payment pre-ordering with a specific resource and output (qr_code). It does not explicitly distinguish itself from sibling tools like alipay_sign_params or alipay_build_pay_url, but the verb and resource are specific enough that the core purpose is 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 provides explicit guidance on the execute flag: execute=false returns a signed request spec, while execute=true performs a real call and returns a QR code. This gives clear context for the two main usage modes, though it does not mention when to prefer this tool over sibling tools or any exclusions.

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 provided, the description carries the full behavioral burden. It discloses the core behavior—RSA2 signing and returning a complete signed parameter set—but it does not mention credential requirements, default timestamp generation, or error behavior. This is adequate but not rich.

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 single, front-loaded sentence with no filler. It states the action, algorithm, output, and intended downstream use in very few words.

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 plus schema is enough for a basic invocation: method and bizContent are required, cred is optional, and the output is a signed parameter set. However, with no output schema and no mention of credential fallback details or usage boundaries, some gaps remain for an agent navigating among many sibling payment tools.

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 80%, so the baseline is 3. The description adds no additional parameter-level meaning, leaving timestamp undocumented, but the schema already explains most parameter purposes.

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 a specific operation: signing Alipay business parameters with RSA2 and returning the complete parameters including sign. It does not name sibling tools, so it misses explicit differentiation, but the verb and resource are specific enough for an agent to understand the tool's role.

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?

Usage is implied by the description: use this when you need to sign Alipay parameters before POSTing to the gateway. However, it does not provide explicit when-to-use or when-not-to-use guidance, nor does it distinguish itself from sibling tools like alipay_precreate or alipay_build_pay_url.

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. It does disclose the verification method (Alipay public key), the required input scope, and the return contract. However, it does not state behavior on verification failure (returns false vs throws), whether the tool is side-effect free, or any other runtime 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?

A single compact sentence that front-loads the action and resource, states required inputs, and gives the return shape. No filler or redundancy.

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 low-complexity verification tool with a rich credential schema and an explicit return contract, the description is nearly complete. The main gaps are explicit failure semantics and a note that this is a pure verification operation with no 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?

Schema coverage is 100%, so baseline is 3. The description adds meaningful semantics beyond the schema by specifying that all callback parameters must be passed and must include sign, and that verification uses the Alipay public key — which clarifies which credential field matters.

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?

Description uses a specific verb (验签/verify signature), a specific resource (支付宝异步通知/Alipay async notification), and states the return shape {valid:boolean}. This clearly differentiates it from the sibling wechat_verify_callback by platform and notification context.

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 makes the intended use case clear: verify Alipay async callback notifications by passing all callback parameters including sign. It does not explicitly name alternatives or state when not to use it, but the Alipay-vs-WeChat platform context is unambiguous from the description and sibling set.

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 it does disclose key behavior: no merchant credentials needed, required environment variables, and return values. It does not mention side effects, error conditions, or idempotency, but the core behavioral profile is reasonably transparent for an order-creation 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?

The description is a single compact sentence that front-loads the platform name and key advantage, then states prerequisites and return values. Every piece of information earns its place with no fluff.

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 covers the essential purpose, prerequisites, and return values, which is enough for a basic call. However, with no annotations, no output schema, and weak parameter documentation, it leaves scene/channel/mchNo semantics under-specified, so an agent may still be uncertain when constructing a full request.

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 only 20% (only 'channel' has a description), and the tool description does not explain any parameters. The phrase '免商户凭证' weakly implies mchNo is not needed, but subject, amountYuan, scene, and channel semantics are left entirely to the schema, which mostly lacks descriptions.

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 creates an order on the 夏天pay hosting platform and returns an order number and cashier link. It distinguishes itself from the direct WeChat/Alipay sibling tools by emphasizing '免商户凭证' (no merchant credentials), though it never names an alternative explicitly.

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?

It gives clear context for when this tool is appropriate: when using the hosted platform without merchant credentials. It also states the required environment variables as prerequisites. However, it does not explicitly say when not to use it or name alternative sibling tools.

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. It adds useful behavioral detail about real-time status valueschers, but it does not explicitly state that the operation is read-only, whether authentication is required, or what happens for unknown/expired order numbers. The 'query' wording implies non-mutating behavior, but more disclosure would be helpful.

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 single concise sentence that front-loads the key action and resource. No extraneous details are included, and the status enum adds useful information without bloating the text.

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 query tool without an output schema, the description gives enough context to select and invoke it: it names the lookup key, the operation, and the expected status values. It could be more complete by mentioning not-found/error behavior, but the low complexity makes the current description nearly sufficient.

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 only defines orderNo as a required string with no description, and coverage is 0%. The description does clarify that the parameter is the order number used for lookup, which adds some meaning. However, it provides no format, source, or additional constraints beyond what the property name already suggests.

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 identifies a specific verb and resource: '按订单号查询实时支付状态' (query real-time payment status by order number). It also enumerates the possible status values (pending/success/failed/expired/refunded), which further clarifies the tool's scope and distinguishes it from sibling creation/verification 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?

The description implies this tool is for checking payment status by order number, but it does not explicitly state when to use it versus the sibling creation or verification tools. There is no mention of exclusions, prerequisites, or typical workflow context such as 'use after creating an order'.

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 must carry the behavioral disclosure burden. It clearly discloses the offline behavior and signature algorithm, which is valuable. However, it does not mention what happens for omitted nonce/timestamp, whether credentials are required, or error behavior, leaving some important traits unspecified.

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 single sentence with no filler. It front-loads the core purpose, then adds the key safety distinction and intended use.

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?

There is no output schema and no annotations, so the description needs to explain the return value and usage details. It omits what the constructed header looks like, how to attach it to a request, and how optional parameters behave. For a tool with six parameters and a nested cred object, this is insufficient.

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 covers url, body, cred, and method, but nonce and timestamp have no descriptions. The description adds no parameter-level meaning beyond mentioning RSA-SHA256 signing, and with 67% schema coverage it should compensate for the uncovered parameters but does not.

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 verb and resource: it constructs an offline WeChat Pay V3 Authorization header using RSA-SHA256 signing. It explicitly says no network request is made, which differentiates it clearly from network-calling siblings like wechat_create_native_order and wechat_verify_callback.

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?

It tells the agent this is for self-built HTTP calls, giving a clear context for when to use it. It does not name alternatives or provide explicit when-not-to-use guidance, but the offline/no-network statement separates it from sibling network tools.

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 provided, the description carries the full burden of behavioral disclosure. It mentions it 'returns prepay_id' and 'invoke parameters', but does not disclose that it actually initiates a payment order with WeChat, which has side effects (e.g., creating an unpaid order, potential charges). It doesn't mention authentication requirements, the need for valid credentials, or the fact that the tool makes a network call. The description lacks behavioral transparency for a mutation-like operation.

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 single sentence that is concise and front-loads the core action (WeChat Pay V3 JSAPI order) and key output (prepay_id and invoke parameters). It is not verbose, but it lacks additional structured information that would be helpful, like usage examples or key parameter clarifications. It is appropriately sized but could be improved with more details without becoming wordy.

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 complexity (5 parameters, nested objects, no output schema, no annotations), the description is incomplete. It does not explain the purpose of each parameter, the required format of the 'order' object (e.g., amountFen in fen), or the meaning of 'execute' (whether it actually sends the request). It does not describe the return structure or error handling. The description leaves significant gaps that an agent would need to infer.

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 description coverage is only 20%, meaning the schema itself does not describe most parameters. The description mentions returning prepay_id and invoke parameters, but does not explain the meaning of 'order', 'openid', 'notifyUrl', or the optional 'execute' flag. It does not clarify that 'openid' is the user's WeChat OpenID required for JSAPI, or the role of 'notifyUrl'. The description adds minimal value beyond the schema's field names.

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 specifies the tool's purpose: creating a JSAPI order for WeChat Pay V3, targeting WeChat in-app or mini-program environments, and returning both prepay_id and the parameters for wx.invoke('getBrandWCPayRequest'). This is specific with verb and resource, and it distinguishes itself from siblings like wechat_create_native_order (which is for Native payments) and alipay_precreate (Alipay).

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 usage context (WeChat in-app/mini-program) but does not explicitly state when to use this tool versus alternatives like wechat_create_native_order, which is for QR code payments. It does not mention that this requires an openid (user authorization) or that it is not for Alipay. The usage guidance is implied but not fully explicit.

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 behavioral disclosure burdenpa. It clearly explains that execute=false returns a signed request spec while execute=true calls the WeChat API and returns a code_url, giving the agent a concrete mental model of the tool's 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?

A single, dense sentence front-loads the core purpose and then explains both execution modes without wasted words. Every clause contributes essential routing or behavioral 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?

There is no output schema, so the description compensates by specifying return expectations for both execute modes. Credential and order parameter details live in the input schema, and the description covers the remaining ambiguity around what each mode returns.

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 covers 75% of parameter descriptions, so the baseline is 3. The main description adds meaningful semantics for the execute parameter by stating the actual outputs for each value, which goes beyond the schema's 'true=真实请求微信；false=仅构造' wording.

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 verb and resource: creating a WeChat Pay V3 Native scan-code order. It also distinguishes the two execution modes, which separates it clearly from sibling tools like wechat_create_jsapi_order and alipay_precreate.

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 'Native 扫码下单' makes the intended use case clear, and the execute flag explains when to sign-only versus actually call WeChat. However, it does not explicitly state when not to use this tool or name alternatives, so it stops short of full exclusion 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?

No annotations are provided, so the description carries the full burden of behavioral disclosure. The description states the algorithm (AES-256-GCM), the key (APIv3), and the output (transaction plaintext JSON), which is useful. However, it does not disclose potential failure modes (e.g., what happens if decryption fails, invalid key, wrong nonce), whether the tool validates the callback signature, or any side effects. For a decryption tool, the behavior is mostly deterministic, but the lack of error-handling context is a gap.

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 single, compact sentence that packs in the purpose, algorithm, key, and output format. It is front-loaded with the core purpose and uses technical shorthand efficiently. It could be slightly more structured (e.g., separating the output statement), but it is appropriately concise for a technical tool.

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 complexity (AES-GCM decryption with multiple parameters, nested cred object, no output schema), the description is somewhat thin. It covers the algorithm and key, but does not explain the relationship between ciphertext, nonce, and associatedData, nor the expected format of the input (e.g., base64-encoded ciphertext). It also doesn't mention that the output is the decrypted transaction JSON, which is stated, but not the structure of that JSON. The cred object's flexibility (env vars vs direct fields) is in the schema, so that's covered. Overall, the description is adequate for a simple decryption tool but lacks detail on input formats and error cases.

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 only 25%, so the description must compensate. The description mentions the key (APIv3) and the algorithm, which relates to the 'apiV3Key' field in the cred object, but it does not explain the meaning of ciphertext, nonce, associatedData, or the cred object structure beyond what the schema provides. The schema has a description for cred (credentials can be omitted, use env vars, PEM fields accept full text or file path), but the other parameters (nonce, ciphertext, associatedData) have no descriptions. The tool description adds context about the algorithm but does not explain the parameters' roles in the decryption process. This is a moderate gap.

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's purpose: decrypting WeChat Pay V3 callback resource data using AES-256-GCM with the APIv3 key, and returning the transaction plaintext JSON. It identifies the specific operation (decrypt), the resource (WeChat Pay V3 callback resource), and the algorithm/key. However, it doesn't explicitly distinguish it from the sibling wechat_verify_callback, which is a related but different operation (verification vs decryption).

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 usage context: it is for decrypting the 'resource' field in WeChat Pay V3 callbacks. It mentions the algorithm and key, which tells the agent when this tool is applicable (when dealing with encrypted callback resources). However, it does not explicitly state when to use this tool versus wechat_verify_callback or other siblings, nor does it provide exclusions or alternative routing. The context is clear enough for a knowledgeable agent but lacks explicit 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?

No annotations are present, so the description is the only behavioral contract. It clearly says verification is done with the WeChat Pay platform certificate and that the result is {valid:boolean}. However, it doesn't describe failure behavior (e.g., invalid signature or certificate), credential sourcing, or whether any network/state effects occur; these details are left to the schema.

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 single two-part sentence: it states the use case first, then the action and return value. No filler words or repeated schema content; it is well front-loaded for quick scanning.

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 verification tool with no annotations and no output schema, the description covers the key selection cue (WeChat Pay V3 callback), the verification mechanism (platform certificate), and the return type (valid boolean). It could be more complete by stating error/edge-case behavior, but the schema covers all parameters completely and the essential invocation contract is present.

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%; timestamp, nonce, signature, rawBody, and cred all have explanatory descriptions, including the instruction that rawBody must not be formatted. The description itself does not add parameter-level detail beyond naming Wechatpay-Signature, so 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?

The description names the exact operation ('验签' / verify signature) on a specific resource ('微信支付V3 异步通知' / WeChat Pay V3 callback notification) and states the return shape. It clearly separates this tool from siblings like wechat_decrypt_callback, which handles decryption rather than verification.

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?

It identifies the triggering context (WeChat Pay V3 asynchronous notification) and the core task (verifying the Wechatpay-Signature with the platform certificate). It does not explicitly mention when not to use it or name alternatives such as wechat_decrypt_callback or alipay_verify_notify, so it stops short of a 5.

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