Identifier Validator + Stablecoin Peg Verdict

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

Goes well beyond the annotations by disclosing data provenance (DefiLlama), staleness (cached 5 min), rate limits (30 calls/hour per client), and a paid x402 path with price and endpoint. This is exactly the operational context an agent needs to decide whether to call and how to handle throttling. Nothing contradicts readOnly/openWorld/non-idempotent hints — live pricing naturally explains idempotentHint=false.

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 verdict taxonomy and metrics; the caching, rate-limit, and x402 pricing clauses each carry decision-relevant information. It is a dense single paragraph with a long URL, but no sentence is pure 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 verdict enum, score range, bps deviation, supply windows, and liquidity. It does not specify the top-level response shape (e.g., array vs object for multi-asset queries), which is the only remaining gap 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?

Schema description coverage is 100%, so both `asset` (symbol/name/DefiLlama id/CoinGecko id, up to 10 comma-separated) and `chain` are already fully documented in the schema. The description only alludes to per-chain output via 'per-chain liquidity' and adds no new syntax or semantics. Baseline 3 is correct.

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 resource (USD stablecoin peg health) and enumerates the exact verdict outputs (PEGGED / WATCH / DEPEG_RISK / DEPEGGED) plus the metrics returned. An agent knows precisely what it gets back. The sibling tools are all unrelated validators, so no differentiation burden exists and none is needed.

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?

Scope limits are explicit: USD stablecoins only, 'live' verdicts, 'informational only, not financial advice'. That tells the agent when the output is appropriate. There is no named alternative or when-not-to-use condition, but the tool has no competing sibling, so the practical gap is small.

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 declare readOnly, idempotent, non-destructive, closed-world behavior, so safety is covered. The description usefully adds the 25-item cap and the set of supported identifier types, but says nothing about what happens when an item is invalid (per-item result vs whole-batch failure), which is the key behavioral question for a batch 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?

A single tight sentence with the batch constraint and the type list front-loaded. Nothing is wasted, though it is arguably too short given the gaps it leaves.

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?

A batch validation tool with no output schema needs to explain the shape of the failure mode (partial results, per-item errors, or an all-or-nothing verdict). Annotations are rich, so the safety profile is fine, but that result-shape gap leaves the definition 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 description coverage is 0%, so the description must compensate. It names the allowable identifier types and the size limit, but is silent on the optional 'country' field and on how items of differing types interact. This partially offsets the coverage gap without fully documenting the nested item 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?

States a specific verb (validate) plus the resource (mixed identifiers) and the batching constraint (up to 25 in one call), which implicitly sets it apart from the single-identifier siblings. It does not explicitly name those siblings, but an agent can tell this is the bulk variant without opening a 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?

The 'in one call' phrasing implies this is for bulk validation rather than single checks, but there is no explicit when-to-use/when-not guidance or a pointer to the per-type validators for one-off cases. Usage is inferable, not stated.

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 declare read-only, idempotent, non-destructive, and closed-world behavior. The description adds meaningful behavioral scope by specifying that it checks structure length and country/location/branch components, though it does not explain what happens or what is returned on invalid input.

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?

One front-loaded sentence with no filler. Every clause adds validation scope rather than repeating the title or schema.

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 one-parameter validator, annotations and the schema cover invocation safety and input. However, with no output schema, the description does not explain return/error behavior on an invalid BIC, leaving a gap for correct interpretation.

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 `bic` parameter is fully described in the schema, and the description adds the 8-or-11-character constraint plus the components being parsed, going beyond the schema's example.

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?

Opens with the specific verb 'Validate' and resource 'BIC/SWIFT code', then names the checked components: structure, country, location, and branch code. Sibling validators target other identifiers, so an agent can distinguish this tool 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?

The name and description imply this tool is for BIC/SWIFT validation, but there is no explicit statement of when to choose it over sibling validators or any exclusions/preconditions. Usage is clear enough to infer, but not fully guided.

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 declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, yet the description still adds genuinely new information: only a masked result is returned and 'nothing is stored'. That privacy/storage guarantee is exactly the kind of trait annotations cannot express. It stops short of saying what the result contains (valid flag, detected network), but the safety profile is well covered.

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, front-loaded with the mechanism and coverage list, then the privacy guarantee. No filler or repetition of the title; every clause carries 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?

For a one-parameter, read-only tool with full schema coverage and strong annotations, the definition covers mechanism, supported networks, and data handling. The only gap is the shape of the response (validity plus detected network), which matters slightly more because no output schema exists to spell it out.

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 the single 'number' parameter already carries a format hint and an example test number (4111111111111111). The description adds no further syntax or length guidance, so the baseline 3 for a fully documented schema 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 the concrete mechanism (Luhn check plus network detection) and enumerates the nine networks covered, so the resource is unmistakably a payment card rather than an IBAN, BIC, or GTIN. It doesn't explicitly name the sibling validators, but the card-network list makes the scope 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?

Usage is only implied by the domain: an agent can infer this is the tool for card numbers, but the description never says when to prefer it over validate_batch or the other validate_* siblings, nor any when-not condition. Adequate but leaves selection to inference.

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 declare read-only, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds the non-obvious detail that only the check digit is validated — not registry lookup or code existence — which meaningfully scopes the result. It still omits what happens with malformed input.

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?

One short sentence, front-loaded with the verb and covered formats, with zero filler. Nothing could be removed without losing 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?

For a one-parameter read-only tool with full annotation coverage, most of what an agent needs is present. The notable gap is the return value: with no output schema, the description never says whether it returns a boolean, a parsed result, or an error, which an agent needs to interpret the call.

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 the single parameter already has an example, so the schema carries the semantics. The description adds no format or normalization guidance beyond it, which is the baseline case.

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?

Names a specific verb (validate) and resource (GTIN-8/12/13/14, EAN/UPC), and specifies that validation means the check digit. An agent can distinguish it from siblings like validate_isbn or validate_card by the identifier family named.

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 only implied: the tool is for checking barcode check digits. Nothing says when to prefer it over validate_batch for multiple codes, nor any exclusions or preconditions (e.g. length normalization).

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 safety (readOnly, idempotent, non-destructive, closed-world), and the description adds value beyond that by disclosing the return payload (validity, country, SEPA flag, formatted IBAN) and, crucially, the limitation that existence of the account cannot be determined. That limitation is exactly the kind of behavioral caveat annotations cannot express.

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: the first front-loads what is validated, the second delivers the caveat. No filler, no repetition of the title.

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, no-output-schema read tool, the description supplies everything needed: the checks performed, the effective return fields, the offline nature, and the scope boundary. Nothing an agent would need in order to invoke it correctly 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 coverage is 100% and already documents that spaces are allowed with an example. The description adds no parameter-level detail beyond what the schema states, 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 (validate) and resource (IBAN) and enumerates the exact checks performed: country rules, length, BBAN structure, mod-97 checksum. This distinguishes it cleanly from siblings like validate_bic or validate_card.

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 'offline' qualifier and the explicit 'structural check only: cannot tell whether the account exists' line set clear expectations about when this tool is appropriate versus an online account-verification service. It stops short of naming a sibling alternative, so it is not a full 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?

The annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered. The description adds genuinely new behavioral information beyond those annotations: that the tool performs check-digit validation and also converts between ISBN-10 and ISBN-13, which an agent could not infer from the annotations or schema 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?

A single front-loaded sentence covering both the validation and conversion capabilities with no filler. Nothing redundant and nothing wasted.

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 single-parameter tool with full annotation coverage this is nearly sufficient, but with no output schema the description leaves the return value undefined — it never says whether the result is a boolean, the normalized/converted ISBN, or both. Since 'convert between the two' implies an output the agent cannot predict, this is a meaningful 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?

Only one parameter with 100% schema description coverage, so the baseline is already 3-4. The description adds meaning beyond the schema by naming the two accepted formats (ISBN-10 and ISBN-13), which the bare schema example of a 13-digit number does not fully 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 (validate) and resource (ISBN-10/ISBN-13 check digit) and adds the secondary capability of converting between the two formats. The resource is distinct enough from siblings (BIC, IBAN, GTIN, VAT, card) that an agent can route correctly, though the description never explicitly contrasts with those validators.

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 name and by the resource being an ISBN, and the 'ISBN-10 or ISBN-13' phrasing signals accepted input formats. However, there is no explicit when-to-use guidance, no statement about what happens with malformed or non-ISBN input, and no mention of when to prefer this over validate_gtin (which also handles 13-digit numbers).

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 declare readOnly/closed-world/idempotent/non-destructive, so the bar is lower; the description still adds real substance by stating the check is offline and limited to format and checksum, which tells the agent no network call or registry verification occurs. It omits what the failure mode looks like (boolean vs. error vs. reason codes), leaving one behavioral 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 short sentences, zero filler, with the capability stated first and the important limitation immediately after. The text is front-loaded and entirely made of decision-relevant facts.

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 2-parameter read-only validator with full schema coverage, the description covers scope, method, and the key limitation. The only shortfall is that with no output schema present, it does not hint at the response shape (valid/invalid flag, error detail), which an agent would need to plan around.

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%, including the 'with or without country prefix' example and the conditional role of 'country', so the schema already does the work and the baseline of 3 applies. The description adds nothing parameter-specific beyond that, which is acceptable here.

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?

Specific verb ('Validate') plus precise resource ('VAT number') with explicit jurisdictional scope ('EU/EEA plus GB, NO, CH and more') and the exact check performed ('format and checksum'). It also carves itself away from any VIES lookup, so an agent can distinguish it from both siblings and non-sibling tax-check tools at a glance.

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 clause 'Does not check VIES registration status' functions as an explicit when-not-to-use rule, and 'offline' signals that it is a local computation rather than a network lookup. It stops short of naming a concrete alternative for registration-status checks, so the routing advice is implied rather than fully closed.

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