Rates by 402rates

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

Annotations already set readOnlyHint=true and openWorldHint=true, so the description adds value beyond that: it discloses the temporal nature ('right now'), the validity period, the scope of the fee figure, and what is intentionally excluded (no table, no runner-up, no components, no provenance). This contextualizes the tool's minimal behavior well without contradicting 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 with zero filler. It front-loads the core purpose and outputs, then explains the costs and tradeoff, then points to the alternative. Every sentence earns its place and the contrast with compare_settlement_costs 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?

For a simple one-parameter, read-only tool with no output schema, the description covers the returned data (fee, scope, validity), the temporal nature, and the minimal scope. An agent can reasonably expect the return to be a simple record containing those fields; a fully explicit JSON shape is absent, but given the tool's intentional minimalism and annotations, this is sufficient.

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

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

The schema documentation already describes the 'chains' parameter with a full list and default behavior (100% coverage), and the description adds no additional meaning about how to format or choose the comma-separated chains. Baseline of 3 is appropriate since the schema carries the parameter semantics.

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

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

The description states a specific verb and resource: 'Returns only the cheapest chain for a USDC transfer' and enumerates the exact outputs (fee in USD, scope, validity). It also differentiates from the sibling paid tool compare_settlement_costs by describing what it deliberately omits, so an agent can tell it apart immediately.

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: this is a free, minimal tool for a single cheapest chain 'right now', while explicitly naming the alternative paid tool compare_settlement_costs that offers full comparison. It does not formally state 'do not use when X', but the tradeoff is evident from the wording, satisfying the 'clear context, no exclusions' level.

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 give readOnlyHint=true and openWorldHint=false, but the description adds key behaviors: it does not perform authentication, does not re-fetch any data, does not reconstruct history, and does not assign economic significance. This meaningfully explains the tool's boundary and fallibility without repeating the annotations verbatim. The 'examples are synthetic' parenthetical is a perfect transparency addition.

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 lean three-point list: purpose, behavior, caveat. It front-loads the primary action and then names exclusions in a tight list. It is not bloated or redundant, though 'Examples are synthetic.' could arguably be dropped or moved to a parenthetical, but it is short and earns its place.

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 no output schema, the description still tells the agent that results are 'threshold crossings' without economic interpretation, and that the tool takes two snapshots plus a threshold in basis points. The schema covers the structure of `after`, `before`, and `threshold_bps`, and the preceding notes about no data access set expectations. The main remaining gap is the absence of an explicit output format, but for a comparison tool this is acceptable because the return is predictable for a human, and the agent can infer it.

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 schema_description_coverage is 100%, the baseline is 3. The description adds a little context by mentioning 'threshold crossings' and 'threshold_bps', but it does not explain how each parameter maps to the comparison logic beyond what the schema already does (e.g., 'before' describes schema_version). The additional 'Issuer origin not confirmed' for `after` is schema content, not description content, so the description adds no new parameter semantics.

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 ('compare') and resource ('two 402rates Treasury snapshots'), then enumerates the exact fields covered (yield, issuer divergence, source identifiers, calculation windows, data availability). It immediately differentiates from siblings like compare_settlement_costs by specifying 'issuer_vs_basis_bps' threshold crossing and 'Treasury snapshots'.

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 tool's purpose itself implies when to use it (whenever you need to diff two saved Treasury snapshots), but there is no stronger 'use this over X' guidance. The description only lists exclusions ('no new data access, no authentication, no historical reconstruction, no automatic monitoring') rather than actively routing the agent away from possible alternative tools. Some of those negatives are constraints, not usage criteria.

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 discloses significant behavioral details: it uses simulated gas, current token prices, fresh chain heads, and rollup L1 fees; it excludes unmeasurable chains rather than estimating them; it orders results cheapest first; and it mentions pricing and terms. No contradiction with annotations. This is rich, helpful context.

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 somewhat long but well-structured, with each sentence contributing distinct information: methodology, output characteristics, exclusion behavior, terms, and pricing. It front-loads the core purpose and avoids fluff. Slightly verbose due to pricing/terms, but acceptable for a paid tool.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

There is no output schema, so the description must explain the return format. It says 'Inputs and block references accompany each figure' and 'cheapest first,' but it does not specify whether the output is a list of objects, units, or exact fields. While the overall behavior is clear, the lack of explicit output structure leaves some ambiguity 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 only parameter 'chains' is fully described in the schema with a comma-separated list and default behavior. The description reiterates the chain names and adds the output ordering (cheapest first), but does not add additional meaning to the parameter itself. With 100% schema coverage, 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 clearly states the tool measures USDC transfer costs across five named chains, with specific details on methodology (simulated gas, token prices, chain heads, rollup L1 fees). It also distinguishes from siblings by noting it provides a comparison ('cheapest first') rather than just identifying the cheapest chain, as implied by the sibling 'cheapest_settlement_chain'.

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 on what the tool does and its scope, but does not explicitly state when to use it over alternatives like 'cheapest_settlement_chain' or when not to use it. The business/professional use note and pricing provide usage conditions, but no direct comparison to siblings. The context is clear, but exclusions/alternatives are absent.

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 and openWorldHint. The description adds the useful scoping fact that it returns only this product and shared service info, but does not describe return format or operational behavior. This is adequate but not rich.

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

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

Two short sentences, directly on topicapper. The first sentence restates the title somewhat, but the second adds a meaningful scoping constraint. No 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?

Low complexity tool with one optional parameter and safe read action; description says what the manifest contains. Does not describe return format, but OpenAPI manifest is self-explanatory; without output schema, a bit more detail would help.

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% for the sole parameter (base_url) and the description adds no parameter-specific meaning. 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 clearly identifies the tool as returning an OpenAPI manifest for 'Rates by 402' and explicitly scopes the contents ('this product and shared service information only'). This is better than a bare verb phraseate but does not fully differentiate from a general 'get manifest' concept.

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 states what the manifest contains but gives no explicit guidance on when to choose this tool over siblings, nor any exclusions. The 'only' phrase implies scope, but there is no direct when-to-use or when-not-to-use guidance.

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

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

Despite readOnlyHint and openWorldHint annotations, the description adds substantial behavioral detail: point fields (value, date, source id, revision, source-time vs read-time dating), a reserved sentinel with data-use URL for five current-only issuer series, and the shared rolling-hour breadth limit. There is 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?

Every sentence earns its place and the core purpose is front-loaded. The density of domain jargon ('reconstructible recorder source', 'HISTORY_SOURCE_RESERVED', 'current-only issuer series') makes it less immediately scannable than a plainer two-sentence definition, so it is not a 5.

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 specifying the per-point return fields, the sentinel/list mode behavior, and the shared breadth limit. Combined with 100% schema coverage and the read-only/open-world annotations, an agent has what it needs to invoke and interpret 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 description coverage is 100%, so the schema already documents all four parameters. The description mostly restates the 'omit source_id' listing mode and 'inclusive date window,' adding only the 'reconstructible recorder source' nuance, which is not enough to lift it past the baseline.

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 opens with a specific verb and resource: 'Returns free normalized observations for one tracked instrument, one reconstructible recorder source and one inclusive date window.' This clearly narrows the tool against siblings like get_rwa_yields or compare_rwa_snapshots, which are about yields or snapshots rather than source history.

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 the main use case (historical observations by source) and gives in-tool query variants such as 'Omit source_id to list the instrument's audited sources.' However, it never names sibling tools or states when to prefer get_rwa_yields or compare_rwa_snapshots, so alternatives and exclusions are left 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 readOnlyHint and openWorldHint, so the description correctly avoids repeating those. It adds valuable behavioral details: the rolling-hour free limit, that repeats stay free, the BREADTH_LIMIT error on exceeding the limit, the existence of a paid snapshot path, and the omitted-ticker list behavior. 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?

The description is three sentences, front-loaded with the core return content and then covering rate limits and the omitted-ticker case. It is efficient with no fluff, though the second sentence is dense and packs multiple conditions (three free, repeats free, fourth returns BREADTH_LIMIT, paid path). Slightly heavy but still well-structured.

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 must explain what is returned and any call-specific constraints. It lists the return components, explains the rate limit and error behavior, and covers the omitted-ticker edge case. For a single-parameter tool with optional input, this is complete enough for an agent to call it correctly without additional documentation.

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 ticker parameter already has a description covering case-insensitivity and the omit-for-list behavior. The tool description reinforces this but adds no new parameter-specific semantics beyond what the schema provides. The rate-limit context applies to overall usage, not to parameter meaning, 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 states a specific verb ('Returns') and resource ('free frozen-contract state view for one tracked tokenized treasury'), and lists concrete contents (identity, yield basis result, evidence cells, deployments, dates). It also clarifies the singular scope and the omitted-ticker behavior, which distinguishes it from the plural sibling get_rwa_instruments without needing to open schemas.

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 clear context: it explains the free-tier rate limit, the BREADTH_LIMIT error on the fourth ticker, and the alternate paid path. However, it does not explicitly name sibling tools or state when to prefer this over get_rwa_instruments or get_rwa_history. The guidance is implicit rather than explicit about alternatives.

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 carry readOnlyHint=true, so the safety profile is covered. The description adds an unusual but important behavior beyond the annotations: the call costs 5 USDC over x402, is licensed for internal use with attribution included, and has a terms URL and separate continuous access terms. It additionally discloses that records match the free instrument view. No contradictions 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?

The description is a dense but well-organized run-on: it opens with scope and contents, then traces the licensing and commercial terms, closing with the x402/Terms URL. Almost every clause earns its place for a paid data snapshot. Minor demerit for restarting the title rather than adding a new angle in the first clause.

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 no-input data-retrieval tool with no output schema, the description compensates well: it enumerates the snapshot, names the free view for comparison, and gives the licensing/price constraints, which an agent must know before a paid call. It is still not exhaustive — the record shape and per-field semantics are left implied by the field list, and a claim about recency/updates is the only clear 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 tool has zero parameters and schema coverage is 100%, so the baseline is 4. The description compensates by detailing what the snapshot contains (fund size, redemption minimums, fees, settlement, access conditions, chain conflicts, quotes, URLs, dates), which is output-oriented but makes clear there is no granularity/editing of input. Nothing more is needed.

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 function: a complete evidence snapshot of the 13 tokenized treasury funds, and lists the fields (yield, coverage, minimums, fees, settlement, chain conflicts, quotes, URLs, dates). That separates it from siblings like get_rwa_yields and get_rwa_history by scope and content, but it never name any sibling, so it falls just short of a 5. The opening phrase also leans on the title, which adds little.

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 context is implied rather than spelled out: 'Same records as the free instrument view' suggests a free alternative, and the licensing sentence says this paid snapshot is for internal/business use with attribution. However, there is no explicit 'when to use this vs. get_rwa_yields', 'get_rwa_history', or other instruments, and no when-not-to-use condition. The agent has to infer the differentiators from the cousin names.

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=true, so the read-only nature is covered. The description adds valuable context beyond that: it discloses a per-call cost (0.03 USDC over x402) and a terms link, plus a professional-use restriction. These are behavioral or operational traits not captured by the annotations. It does not contradict the annotations or introduce ambiguous behaviors, so a 4 is appropriate.

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 longer than minimal but each sentence earns its place: the primary purpose is front-loaded, followed by methodological details, data features, restrictions, and finally pricing/terms. It is well-organized and not redundant, though it could be slightly more compact by merging some clauses. Overall, it is structured effectively without being bloated.

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 data retrieval tool with no output schema, the description provides a solid overview of what the response will contain: rows with observations, sources, dates, issuer figures, differences, and explicit handling of unavailable/quoted rows. It also notes coverage lists and gaps. It does not specify the exact response structure, but it conveys the semantic content well enough for an agent to understand the return. The addition of cost and terms further completes the operational context.

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 has 100% description coverage for the only parameter ('instruments'), fully documenting the comma-separated format and default behavior. The tool description itself adds no further parameter detail, but since the schema already handles it, the baseline of 3 is correct. The description does not need to repeat what the schema already 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 states a specific verb-resource pair: 'Realised 30-day yields' for tokenized treasury funds, and names the specific universe (13 funds under the Open Treasury Yield Basis). It also details what measurements include (NAV, price, balances) and what is explicit (quoted/unavailable rows). This clearly distinguishes it from siblings like get_rwa_history or get_rwa_instrument, which pertain to historical or single-instrument data.

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 provide any explicit guidance on when to use this tool versus alternatives. It mentions a business/professional use restriction and terms, but nothing about selecting it over siblings. There is no statement like 'use this for current yields' or 'for historical data use get_rwa_history'. The only implied context is the tool's own name and content, but no exclusions or alternatives 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?

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safe-read nature is covered. The description adds that the catalogue is free and limited to product/shared-service information, which is useful context. It does not contradict the annotations and provides a modest amount of additional behavioral scope.

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 filler. The key identifier, 'capability and MCP tool catalogue for Rates by 402rates', is front-loaded, and the scope qualifier is a necessary clarification. Every word earns its place.

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, read-only catalogue tool with annotations covering safety and open-world hints, the description is sufficient. It defines the resource, the scope, and the product context. It could mention what a returned catalogue contains, but the absence of an output schema and the simplicity of the tool keep the gap minor.

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 description does not need to explain parameter semantics. The empty schema fully covers the input surface, and the description's claims about containing product/shared service information are consistent with a zero-parameter catalogue tool.

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 the tool as a 'capability and MCP tool catalogue' for 'Rates by 402rates', which makes the resource and scope clear. It lacks a strong verb, but the title's 'List' plus the catalogue wording convey the purpose. The phrase 'Contains this product and shared service information only' helps distinguish it from feature-specific tools.

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

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

The description implies this is the entry point for discovering available tools and capabilities. It does not explicitly state when to use it versus sibling tools or provide exclusions. The 'this product and shared service information only' qualifier gives some scope guidance but no direct routing.

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