Hex encode, input discarded

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

With no annotations, the description carries the full burden. It only mentions that page content is not stored, but omits crucial behaviors such as redirect handling, error responses, rate limits, or side effects. The agent cannot predict the tool's runtime behavior reliably.

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 to the point, but it is incomplete. It lacks a clear structure that maps to the schema, and the single sentence does not cover the full scope of inputs or outputs.

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 sibling tools (normalize-url, validate-json, timezone, etc.), the description does not position this tool within the broader context. It fails to clarify how citation differs from normalization or validation, and the output format is 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?

The schema includes descriptions for each parameter, but they are generic and conflict with the tool's stated purpose. The description does not explain why 'host', 'json', or 'zone' are inputs for a URL citation tool, leaving the parameter meanings ambiguous and inconsistent.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific action ('Return host, scheme, and HTTP status for a URL') but does not clarify the role of other parameters (host, json, zone) in the schema. It also fails to distinguish this tool from siblings like normalize-url or status-catalog, which may overlap in functionality.

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?

No guidance is provided on when to use this tool versus alternatives. The description gives no conditions, prerequisites, or contextual cues to help an agent select it appropriately.

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 disclosing behavior. It adds one useful privacy note ('No identifiers are retained') but omits whether the operation is read-only, what side effects occur, what the output format is, or any auth/rate-limit constraints. The phrase 'show how this request is classified' is vague about the actual action.

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 two short sentences with no wasted words, but it is under-specified. It is structurally efficient but does not front-load enough useful information about purpose or usage to be considered well-crafted.

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 4 optional parameters, no output schema, and no annotations, the description must explain what classification means, what inputs to supply, and what output to expect. It only offers a cryptic purpose and a privacy note, leaving the agent without enough guidance to call the tool correctly.

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 cover 100% of the parameters, each with a clear meaning (e.g., 'JSON text to validate; discarded after the check'). The description adds no parameter-specific meaning beyond the schema, only a general privacy statement. Given the high schema coverage, a 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 'Show how this request is classified' states a general action but does not specify what 'classified' means or what resource it operates on. It does not mention the tool's name 'compatibility' or connect to any specific kind of classification, and it does not distinguish this tool from siblings like 'validate-json' or 'status-catalog'.

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. No mention of suitable scenarios, prerequisites, or exclusions. An agent cannot decide between this tool and sibling tools like 'normalize-url' or 'timezone' based on the description alone.

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 provides no information about side effects, permissions, or data handling. It does not state whether the tool is read-only, performs network calls, or modifies any state. The 'without WHOIS' phrase could be interpreted as a behavior constraint, but it is too vague to be informative. With no annotations provided, the description carries full responsibility, and it fails to disclose any behavioral traits.

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, consisting of a single sentence that conveys the primary function in a few words. It is not verbose or redundant. The short length is appropriate for the simple purpose stated, though it sacrifices clarity around parameters. In terms of structure, it is front-loaded with the action ('Split a hostname') and immediately clarifies a limitation ('without WHOIS or data ownership').

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 is severely incomplete given the mismatched parameters and lack of output specification. An agent cannot determine how the four parameters (url, host, json, zone) relate to the 'hostname to labels' operation, what the expected output format is, or whether all parameters are required (since none are marked required). The description leaves crucial context missing, making the tool difficult to use correctly without external information.

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 parameter descriptions are grossly mismatched with the tool's stated purpose. For example, 'url' is described as 'HTTPS URL to normalize or cite' (unrelated to splitting hostnames), 'json' as 'JSON text to validate' (unrelated), and 'zone' as 'IANA timezone name' (unrelated). Only 'host' ('Public hostname') aligns with the purpose, but its description is shallow and does not clarify the expected format or relationship to the other parameters. The descriptions actively mislead rather than clarify, providing no meaningful semantic value.

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 core purpose is stated clearly: 'Split a hostname into labels' and the qualifier 'without WHOIS or data ownership' adds context about what the tool does not do. However, the parameter descriptions (URL, JSON, timezone) are unrelated to this purpose, which creates confusion about the actual input expected. The purpose sentence itself is specific enough, but the mismatched parameter descriptions slightly obscure the intent.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description offers no explicit guidance on when to use this tool versus alternatives. The phrase 'without WHOIS or data ownership' hints at a use case boundary (e.g., not for ownership lookups), but it does not mention sibling tools like normalize-url or validate-json, nor does it explain scenarios where domain-shape is preferred. No concrete when-to-use or when-not-to-use instructions are given.

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 phrase 'input discarded' offers some hint about behavior, but it is ambiguous and does not explain side effects, return values, or whether the tool modifies state. Since no annotations exist, the description carries the full burden but fails to provide clear behavioral details.

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 short, but brevity is not beneficial when it omits essential information. It lacks structure and fails to convey a clear message, making it inefficient despite its minimal length.

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 sparse and misleading description, along with mismatched parameter definitions, the tool is incomplete from a contextual standpoint. An agent cannot reliably understand what the tool does, what inputs to provide, or what to expect as output.

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 descriptions for parameters (url, host, json, zone) are inconsistent with the tool's apparent purpose. For example, 'url' is described as 'HTTPS URL to normalize or cite', which is irrelevant to hex encoding. The parameter semantics do not align with the tool's function and add confusion rather than clarity.

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 'Hex encode, input discarded' is vague and contradictory. It suggests encoding but then mentions discarding input, leaving unclear what the tool actually does. It does not name a specific resource or clearly distinguish it from sibling tools like validate-json or normalize-url.

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. No conditions, prerequisites, or examples are provided, leaving the agent without any direction on selection.

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 disclosing behavioral traits. The description reveals nothing about side effects, network usage, read-only status, or what the tool returns. It is merely a label with no behavioral information.

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 short sentence, but it is under-specified rather than concisely informative. It does not front-load essential information about the tool's function or behavior. It is more of a vague tag than a structured description, so it fails the conciseness criterion.

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 is complex with four parameters and no output schema, yet the description is extremely incomplete. It does not explain what the tool does, what it returns, or how the parameters relate to its operation. An agent cannot determine how to invoke it correctly from this definition.

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 covers 100% of parameters with descriptions: url (HTTPS URL to normalize or cite), host (Public hostname), json (JSON text to validate; discarded after the check), and zone (IANA timezone name). The tool description adds no additional meaning beyond these, so the baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description 'Common IANA timezone names for clock calls' is a noun phrase that does not state an action. It implies the tool provides a list of timezone names, but it does not clearly say what the tool does (e.g., 'List common IANA timezone names' or 'Return a set of timezone names'). It also does not distinguish it from siblings like 'timezone' or 'utc-time' which likely handle timezone conversions. The purpose is vague.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no guidance on when to use this tool versus alternatives. Sibling tools such as 'timezone', 'utc-time', 'normalize-url', and 'validate-json' overlap with the parameters (url, json, zone), but the description gives no hints about when to select this tool over them. An agent is left to guess.

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?

Without annotations, the description carries the burden of explaining behavior. It does state that it fetches a public resource and returns only group counts, which is transparent. However, it does not disclose potential network errors, rate limits, or the fact that the parameter descriptions are inconsistent with the tool's purpose, which confuses rather than clarifies.

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 (one sentence) and front-loaded with the primary action. However, it lacks a clear structure to separate purpose, parameters, and output. The brevity leaves out essential details that would make it well-formed.

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 and schema together are incomplete and contradictory. There is no output schema, no indication of which parameters are required, and no explanation of how the parameters relate to the tool's function. An agent would be unable to correctly invoke this tool based on the provided information.

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 lists four string parameters, but their descriptions are mismatched: 'url' is 'HTTPS URL to normalize or cite', 'json' is 'JSON text to validate', and 'zone' is 'IANA timezone name'. None of these align with the stated purpose of fetching robots.txt. The tool likely only needs a URL or host, but the schema and descriptions do not convey this, making parameter usage unclear and misleading.

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 ('Fetch') and resource ('public robots.txt') and clarifies the output ('return group counts only'). It is distinct from sibling tools like 'normalize-url' or 'validate-json', though it could be more explicit about its intended use case.

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 no guidance on when to use this tool versus alternatives. It does not mention that this is for checking robots.txt rules or that it is preferable to other tools for this purpose. No context is given for selecting 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?

With no annotations, the description carries the transparency burden and does disclose a key behavior: dropping query and fragment. However, it omits error handling, edge cases like invalid URLs, and potential side effects.

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 two concise sentences with no unnecessary wording, making it easy to parse.

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?

While the tool is simple, the description lacks a return format or example and fails to reconcile the schema parameters (host, json, zone) with the URL-normalization purpose. An agent cannot confidently determine the correct arguments to pass.

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 lists four parameters (url, host, json, zone) but their descriptions are inconsistent with the stated purpose; json and zone appear unrelated to URL normalization. The tool description adds no clarification for these parameters, leaving them highly ambiguous.

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 returns origin, host, and path for a URL and drops query/fragment, making the core purpose specific and actionable. However, it does not explicitly differentiate from sibling tools like domain-shape or status-catalog.

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?

No guidance is provided on when to use this tool versus alternatives. The only implicit hint is that query/fragment are dropped, but there is no explicit when/when-not 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?

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only says the tool is a 'short catalog', leaving unclear how inputs are used, what output to expect, and whether the operation involves network calls or local lookup. This is a notable 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 short sentence with no wasted words, front-loading the core topic: HTTP status codes. It could be expanded to include a verb or relation to the inputs, but as concise it is efficient.

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 four parameters, no output schema, no annotations, and many siblings that overlap on those parameters. The description fails to explain why these particular parameters are relevant or what output the agent should expect. This is incomplete for a tool with multiple optional inputs.

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 has 100% description coverage for all four parameters, so the schema already explains url, host, json, and zone. The description adds only that the tool is a catalog of HTTP status codes, which does not clarify how any of these parameters connect to the catalog. 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 indicates the resource (common HTTP status codes) and implies a catalog/retrieval function, but it lacks a verb and doesn't specify what operation is performed. It doesn't differentiate itself from sibling tools that share overlapping parameters like url, host, json, and zone.

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 like citation, validate-json, or normalize-url. The description gives no context for selecting this tool, no prerequisites, and no 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 burden of disclosing behavior. It implies a read-only operation by stating 'current time', but does not explicitly mention side effects, permissions, or the fact that it is safe. The mismatch between the description and the schema parameters (url, host, json) further muddies the expected behavior.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, concise sentence that conveys the core functionality without unnecessary words. It is well-structured and easy to parse.

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 is too brief to explain the presence of multiple parameters (url, host, json) that seem unrelated to timezone lookups. It lacks context about why these parameters exist or how they interact with the primary operation, leaving gaps in understanding for an agent.

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 provides descriptions for all parameters, so the baseline is 3. The tool description does not add any additional meaning about parameters; it only mentions 'named IANA timezone' without explicitly linking it to the 'zone' parameter. This leaves the relationship between the description and the actual parameters unclear.

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 that the tool returns the current time for a specified IANA timezone, which is a specific and unambiguous purpose. It distinguishes itself from sibling tools like 'utc-time' by focusing on named timezones.

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 does not explicitly mention when to use this tool instead of alternatives such as 'utc-time'. The context is implied but not stated, so an agent may need to infer the appropriate use case from the name and description.

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 and a description that only mentions a timestamp, there is no disclosure of side effects, safety, or any behavior beyond the immediate output. The mismatched parameters further obscure what the tool actually does.

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 brief and front-loaded, but it omits essential context about the parameters and expected input/output structure. Brevity does not compensate for the lack of actionable 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?

There is no output schema, no request/response examples, no notes on error conditions, and no explanation of how the parameters influence the result. The tool is far from complete for an agent to use correctly.

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?

Although the schema includes descriptions for each parameter, those descriptions (e.g., 'HTTPS URL to normalize or cite') have no connection to the stated purpose of returning a UTC timestamp, making the parameters misleading and functionally 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 states 'Current UTC timestamp,' which gives a clear output, but the parameters (url, host, json, zone) are unrelated to that purpose, making the actual function ambiguous and self-contradictory.

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?

No guidance is provided on when to use this tool, what problem it solves, or how it relates to sibling tools like timezone or validate-json. The description offers no context for selection or invocation.

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 discloses that the body is discarded, which is a behavioral detail. However, it does not explain what 'body' refers to, nor does it clarify the roles of the url, host, and timezone parameters, which appear unrelated to JSON validation. This lack of explanation reduces transparency about how the tool actually processes its inputs.

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, consisting of two short sentences. It conveys the purpose and a key side effect without any unnecessary words or filler, making it highly efficient.

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 is missing essential context about the tool's inputs. The presence of unrelated parameters (url, host, timezone) alongside 'json' creates confusion about what the tool actually does. The description does not explain why these parameters exist or how they relate to validating a JSON body, leaving significant gaps in understanding.

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 description adds no explanation for any parameters. The schema itself provides descriptions for each field, and the json parameter's schema description aligns with the tool's purpose. Since schema coverage is 100%, the baseline is 3, and the description neither enriches nor detracts from the parameter meanings.

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: 'Check whether a body is valid JSON.' It uses a specific verb ('Check') and specifies the resource ('body'), making the core function unambiguous. The name 'validate-json' exactly matches the description.

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 alternatives. It does not mention any conditions, prerequisites, or contexts in which validation is appropriate. The sibling tools like normalize-url and timezone are not referenced, leaving the user to infer the tool's applicability.

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