Compass by 402rates

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

The description goes beyond the annotations (readOnlyHint=true) by detailing what it does NOT do: 'No wallet connection, external fetch, signature verification or settlement,' and notes that other profiles are untested. This adds significant behavioral context that an agent would need to avoid misuse. There is no contradiction: readOnlyHint aligns with the inspection-only nature.

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 concise and efficient: three sentences that front-load the primary function ('Free inspection...') and immediately clarify exclusions. Every sentence adds value: the first defines the action, the second clarifies scope and constraints, the third lists what is not done. No fluff 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?

Given that there is no output schema, the description explains the input structure (via schema) and the purpose clearly. For a read-only inspection tool with schema coverage, it does not need to explain return values, but it could have mentioned expected output format (e.g., validation result). However, since the tool is largely self-contained and safe, it is complete enough for correct invocation.

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 input schema already has detailed descriptions for both parameters ('expected' and 'challenge') and covers all parameters (100% coverage). The description adds meaning by clarifying the constraints (network, asset, etc.) and the read-only nature, but the schema itself is strong. Since coverage is 100%, the baseline is 3, and the description does not add substantial parameter-specific detail beyond what the schema provides.

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 verb ('free inspection'), the resource ('supplied x402 v1/v2 payment terms'), and what it does (checks against the SDK schema and optional constraints). It distinguishes itself from siblings by specifying it is a read-only inspection, not a payment action, and notes that other profiles are untested.

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 this tool: for read-only validation of payment terms without wallet connection or settlement. It lists constraints (network, asset, recipient, atomic budget) that guide usage. However, it does not explicitly state when not to use it or mention alternatives like 'test_payment' for actual payment testing, but the context is clear enough for an agent to infer.

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?

The read-only, non-destructive profile is already carried by annotations; the description adds value beyond them by disclosing that the call is free of payment/wallet interaction and that omitting case selection defaults to the original confirmation case. No contradiction with 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?

Three terse sentences, each earning its place: what the tool describes, the default-selection behavior, and the exclusions. The most important job-identifying information is front-loaded with zero 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?

For a zero-required-parameter read tool with fully documented schema and safety annotations, the description covers purpose, default behavior, and exclusions well. Minor gap: it doesn't describe the shape of the returned description beyond 'limits and coverage,' and there is no output schema to compensate.

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 earns an extra point by explaining the omission semantics — selecting no case yields the original confirmation case — which the schema's 'Versioned synthetic case identifier' does not convey.

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: it 'describes' a 'versioned synthetic task, its limits and coverage.' The closing clause 'No run, payment or wallet' explicitly differentiates it from sibling tools like start_agent_test, test_payment, and check_payment_terms, so an agent can pick it without opening the 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 the optional-case behavior ('omitted selection describes the original confirmation case') and an explicit when-not signal ('No run, payment or wallet'). However, it never names an alternative tool to use when a run or payment is actually needed, stopping short of full routing.

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?

Beyond the annotations, the description discloses idempotent replay on identical keys/input, observability of calls/effects/simulated credits, and the absence of real payment. These are precisely the behavioral details an agent needs before invoking a synthetic execution tool. There is no contradiction with 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?

Three short sentences, front-loaded with the verb and action-kind list, with each sentence adding distinct operational information: scope, replay behavior, observability, and no-payment guarantee. There is 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?

The schema plus description is adequate for understanding parameters and general behavior, but there is no output schema and the description omits the expected response shape and sequencing prerequisites, such as when a selected case is ready to execute after start_agent_test. For an 8-parameter execution tool, this leaves the agent to infer post-call behavior.

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 descriptions already cover all 8 parameters, so the baseline is 3. The description adds operation-level meaning by explaining that identical keys and input replay stored outcomes and by restating action_type values in plain language. It does not add per-parameter details beyond that, so it does not reach 5.

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 identifies a concrete operation, 'Execute the selected case's action', and enumerates the supported action kinds: synthetic order, retry attempt, page retrieval, or result submission. This is specific enough to separate it from sibling list/read/inspect/start tools, though it does not explicitly name a sibling alternative.

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 wording implies the tool is for synthetic execution after a case has been selected/started, and 'No real payment' signals a boundary against real-payment flows. However, it never explicitly tells an agent when to use this tool instead of inspect_test_state, read_agent_test_report, or test_payment.

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?

Beyond the readOnlyHint and openWorldHint annotations, the description adds valuable behavioral context: every figure is a count with its definition, no entry is scored/rated/labelled, answers come from a dated weekly snapshot, and the tool is free. This fully discloses what the agent can and cannot expect, with no contradiction to 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?

The description is three sentences, each earning its place: the first states the core function and outputs, the second clarifies the data's neutral nature, and the third addresses freshness. It is front-loaded and avoids 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?

With no output schema, the description covers the main return fields (price, chains, usage counters) and the snapshot date, which is sufficient for an agent to know what to expect. It could mention ordering or pagination, but those are minor given the limit parameter and the tool's straightforward search nature.

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 input schema already covers 100% of the parameters with detailed descriptions (e.g., q has whole-word matching and no stemming, limit has range, network gives chain id format, max_price is in USDC). The description adds no additional parameter-level meaning beyond what the schema provides, so the baseline of 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 states a specific verb ('Searches'), a clear resource ('x402 resource catalogue'), and enumerates what it returns (matching paid endpoints with price, chains, and 30-day usage counters). It clearly differentiates itself from the sibling tools, none of which are resource-search tools, so an agent can immediately recognize this as the catalogue lookup.

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 a clear context for use — searching for paid x402 endpoints — and includes the useful note that omitting q lists resources with the broadest paying base. It does not explicitly name alternatives or state when not to use it, but no sibling performs an equivalent catalogue search, so the absence of exclusion guidance is a minor gap.

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?

The description reveals the content scope ('this product and shared service information only') and the readOnlyHint annotation covers safety. It does not explicitly state the output format beyond the phrase 'OpenAPI manifest,' which is a minor 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?

Two concise sentences immediately identify the tool's purpose and content scope. It is properly front-loaded and has no unnecessary detail.

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 read-only, single-parameter tool, the definition plus schema is enough to call it correctly. It could be more explicit about the exact response shape, but an OpenAPI manifest is a well-known format and no output schema exists to fill that gap.

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 single optional parameter is already described in the JSON schema ('absolute origin to render into the manifest's servers block'), so the description adds no new parameter guidance, but the schema fully compensates.

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 what is being retrieved: an OpenAPI manifest for Compass by 402rates, and states what it contains. It is concise and unambiguous, though it does not explicitly distinguish itself from 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?

There is no guidance on when to use this tool versus alternatives such as list_capabilities or find_resource. The description states what the tool returns but not when an agent should choose it.

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 already cover readOnlyHint, destructiveHint, and openWorldHint. The description adds meaningful caveats beyond those: observations describe the test service only, and no claim is made about client receipt or overall agent reliability. This helps the agent interpret return values correctly, though it does not go as far as documenting pagination or exact output shape.

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?

Three short sentences, each earning its place: the first states the core action, the second scopes the data source, and the third clarifies the limits of what the observations mean. 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 simple read-only tool with complete parameter documentation and strong safety annotations, the description covers the essential interpretation of returned data. It could be more complete by specifying the output structure or referencing the report sibling, but the current description gives an agent enough to call it and understand its caveats.

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 the schema already documents run_id, task_id, and access_token fully. The description adds no parameter-specific meaning beyond what the schema provides, 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 a specific verb and resource: 'Read operation records for a synthetic task.' It also adds scope with 'Observation timestamps and state describe the test service only.' It is clear, but it does not explicitly distinguish itself from near-sibling read_agent_test_report, so it stops short of the best possible differentiation.

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 operation records/observation state for a synthetic task. However, it gives no explicit when-not-to-use guidance, prerequisites, or alternatives among the sibling tools, so an agent must infer the correct selection context.

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 already mark the tool as read-only and non-destructive. The description adds useful behavioral context by noting that the tool is only exposing a catalogue and involves no run, wallet, or payment side effects. It does not detail return format or pagination, but for a zero-parameter read-only list tool this is a minor gap rather than a significant one.

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 concise: a two-sentence summary, front-loaded with the core purpose ('Free catalogue of versioned synthetic cases') and followed by a clear boundary statement. 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?

Given that the tool has no parameterschers, no output schema, and is a simple read-only list operation, the description is largely complete. It tells the agent what the catalogue contains, that it is versioned, and that it does not execute or involve payments. A slightly stronger definition might state what fields each catalogue entry contains, but this is not essential for correct invocation.

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 parameterserd and the schema is empty, so the baseline is 4. The description provides no parameter-related information, but none is needed because no parameters exist.

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 title and description together clearly identify this as a listing operation for synthetic test cases. The description enumerates what the catalogue contains (versioned synthetic cases, including confirmation, attempt limits, and continuation scenarios) and explicitly states what it is not for ('No run, wallet or payment'), which distinguishes it from related execution or payment 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 gives clear context: this is a read-only catalogue of test cases araivalable for inspection, not for execution or payment. It does not explicitly name alternatives like describe_agent_test or execute_test_action, but the 'No run, wallet or payment' phrasing effectively steers the agent away from execution tasks.

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 already communicate read-only and open-world behavior. The description adds a useful scope limitation ('Contains this product and shared service information only'), but it does not describe the output format, pagination, or whether this is a static catalogue.

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 brief and front-loads the tool's purpose and scope without extraneous detail.

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 zero-parameter listing tool, it is mostly complete, but it could clarify what a returned catalogue entry looks like (e.g., capability names, descriptions, availability) since there is no output schema and the sibling tools are action-oriented rather than informational.

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)Skip, so the schema fully covers the parameter surface; the description appropriately implies an unparameterized listing operation.

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 title and description clearly identify this as a catalogue-listing tool for Compass by 402rates, covering product and shared-service capabilities. The purpose is specific and matches the tool name, though the description itself lacks a direct action verb like 'list'.

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 no explicit guidance on when to call this tool versus siblings such as find_x402_resource, get_manifest, or list_agent_test_cases. The scope boundary is stated, but no alternatives or conditions are mentioned.

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?

The description goes beyond the annotations by disclosing what the report contains, that optional finalization 'freezes the run,' that a linked repeat includes the previous frozen report while retained, and that the tool produces no judgment of the agent. This meaningfully explains side effects and non-behaviors beyond the readOnlyHint=false and destructiveHint=false annotations. There is no contradiction with 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?

The description is short and front-loaded, opening with the primary read action and following with finalization, linked-repeat behavior, and a clarifying note about no scoring. Each sentence earns its place, though 'while retained' is slightly vague.

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 tool with three simple parameters, no nested objects, and no output schema, the description covers the main content of the report, the finalization side effect, and the absence of evaluative judgment. It does not describe exact response formatting or error cases, but the absence is not critical given the low complexity and strong schema coverage.

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 parameter is already well documented: run_id is the identifier from start_agent_test, finalize controls freezing, and access_token is a secret short-lived token omitted from reports. The description adds little beyond what the schema provides, so the baseline score of 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 states a clear verb and resource: 'Read calls, timestamps, operations and resulting state' and 'finalization freezes the run.' It gives enough specificity about what the report contains and the optional finalize behavior. It does not explicitly name a sibling alternative like inspect_test_state, but the phrasing is distinct enough for an agent to identify this as the report-reading/finalizing tool.

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 to read or finalize an agent test timeline, and the 'No score, certification or judgment' sentence gives a meaningful exclusion. However, it does not explicitly state when to prefer this over inspect_test_state or other siblings, nor does it describe conditions such as run completion or token validity.

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 minimal annotations, the description carries the behavioral burden and adds valuable traits: the run is free, bounded, account-free, non-purchase, and caller model costs remain external. It does not contradict the readOnlyHint=false/destructiveHint=false annotations, and it gives more context than the annotations alone.

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 four short sentences with no filler, and the core purpose is front-loaded in the first sentence. Economic and repeat-mode details each earn their place 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 six-parameter tool without an output schema, the description covers the main preconditions (no account), side effects/costs (free, bounded, no purchase, external model costs), and repeat semantics. The parameter schema fills the remaining invocation details, though the exact return payload is left unspecified.

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 the structured fields already document case_id, variant, access_token, case_version, previous_run_id, and configuration_changed. The description adds the relationship that a finalized previous run plus its token triggers a linked repeat, but it does not need to compensate for schema gaps.

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+resource ('Create a free bounded synthetic run') and explains the repeat mode ('An optional finalized previous run and its token link a repeat of the same case version and scenario'). This clearly separates start_agent_test from sibling tools that describe, inspect, list, or read test artifacts.

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 to use the tool: creating or repeating a synthetic run without an account, and it explicitly signals that no real purchase is involved, which avoids confusion with payment-related siblings. It does not name explicit alternatives or when-not-to-use conditions, 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.

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

Beyond the readOnlyHint and openWorldHint annotations, the description adds that the call costs 0.001 USDC, performs no external data lookup, and returns specific fields (time, rail, network mode, capabilities). It also mentions that the result may vary by 'challenge' (aligning with openWorldHint). This context is valuable and does not contradict 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?

The description is a single paragraph that efficiently packs cost, output fields, network options, receipt details, and terms. It is not overly verbose, but the structure could be improved by front-loading the main purpose more clearly; it currently mixes output details with terms and price, yet remains reasonably concise.

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?

Despite having no parameters and no output schema, the description provides a solid overview of what the tool returns, its cost, network options, and terms. It does not cover error handling or prerequisites, but for a simple read-only check, it is fairly 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?

The tool has no parameters, so the input schema fully covers parameter semantics (baseline 4). The description adds nothing about parameters, but since there are none, this 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 clearly states it is a payment integration check that returns time, rail, network mode, and free/paid capabilities, and it specifies the cost and that no external data lookup occurs. While it distinguishes itself from some siblings by mentioning 'no external data lookup', it does not explicitly name alternative tools, so it is clear but not explicitly differentiated.

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 no guidance on when to use this tool versus its many siblings (e.g., cheapest_settlement_chain, check_payment_terms). It only mentions business/professional use and availability of terms, but no context about when it is the appropriate choice or when to avoid it.

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