NEMO x402 Micro-Services

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

Annotations already declare readOnly/idempotent/non-destructive, and the description still adds real value: the payment rails (Base first, Solana also accepted) and the requirement that the caller hold a wallet able to pay x402. It omits return shape and any rate/limit behavior, so not a 5.

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

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

Two short sentences with the catalogue contents front-loaded and no filler. The second sentence is slightly telegraphic ('Paid work is those HTTP URLs') but still earns its place by tying output to the x402 payment flow.

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 parameterless, no-output-schema listing tool this covers what comes back (routes, prices, rails) and the caller prerequisite (x402-capable wallet). The only gap is how to distinguish this from agentx_x402_doctor.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool takes zero parameters, so the baseline is 4 and there is nothing for the description to disambiguate. No parameter-related content is needed 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?

States a specific verb (List) and resource (AgentX live services) and enumerates the payload of interest: routes, prices and USDC rails. It does not differentiate from the sibling agentx_x402_doctor, so an agent must infer the split itself.

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: this is the discovery step whose output is 'the paid work' you then call with an x402-capable wallet. There is no explicit when-to-use versus agentx_x402_doctor, and no stated preconditions beyond needing a paying wallet.

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 and destructiveHint=false, so the safety profile is covered. The description usefully adds that the check is version-aware ('v1+v2 aware') and returns a verdict, grade, networks and USD prices, and that it is free via MCP — meaningful context beyond 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?

One dense sentence with the purpose front-loaded and zero filler; the parenthetical efficiently bundles the return-value hints. It earns its place almost entirely, though the tagline suffix is slightly marketing-flavored.

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 what the verdict contains (grade, networks, USD prices) and that it is free. For a single-parameter read-only validator, an agent has everything needed to call it 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 coverage is 100% and the single url parameter is fully documented, so the baseline is 3. The description adds only that the URL should be a paid endpoint and that it accepts 'any URL', which is marginally beyond the schema.

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 ('check whether') and a precise resource ('any URL is a valid, agent-payable x402 resource'), so the agent knows exactly what the tool does. It does not, however, differentiate itself from the sibling nemo_x402_catalogue, so it falls short of the 5 tier.

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 — validating an x402 URL before treating it as payable — but there is no explicit statement of when to reach for this instead of nemo_x402_catalogue, nor any exclusions. Adequate but leaves the routing decision 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?

The description adds critical temporal and status information (deprecated status, renaming date: 21 Oct 2026) that is entirely separate from the standard safety annotations provided.

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 highly efficient, front-loading the most crucial information (deprecation status and renaming) without any unnecessary jargon.

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 zero parameter count and rich annotations, the description is complete by addressing the tool's lifecycle status and migration path for the AI 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?

Since the tool has zero parameters, the baseline for semantics is high. The description does not need to provide parameter meaning, and the schema coverage is 100% anyway.

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 purpose is clear through the name and context, but the description primarily focuses on the tool's status as a deprecating alias rather than detailing the specific functionality of the catalogue look-up itself.

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 extremely explicit usage instructions, directing new callers to the primary tool (agentx_x402_catalogue) while maintaining the alias for existing clients.

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 and destructiveHint=false, so the safety profile is covered elsewhere. The description adds the useful guarantee that the response is identical to the successor's, but says nothing about network cost, latency, failure modes, or what happens with an invalid/non-HTTPS url.

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 deprecation status and immediately followed by the migration instruction. The 'takes a url parameter' clause is the only near-redundant fragment and could be dropped without loss.

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, read-only deprecation alias with a fully documented schema and no output schema, nothing an agent needs to decide whether to call it is missing. Migration path, equivalence to the successor, and parameter shape are all covered.

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 the url parameter's format, HTTPS requirement, and purpose are fully documented in the schema. The description only restates that it 'takes a url parameter,' adding no meaning beyond the schema, 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?

The description states the tool is a 'Deprecated alias of agentx_x402_doctor' and that it is the same check with the same response, which lets an agent place it relative to the named sibling. It stops short of saying what the check actually does (spec-checking a paid endpoint), leaving that to the schema's url 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?

Explicit routing guidance: new callers should use agentx_x402_doctor, while the alias remains for existing clients. The when-to-use and when-not-to-use conditions are both spelled out, and the successor tool is named exactly.

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