Solana MCP by Vybe

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

Annotations already indicate destructiveHint=true and readOnlyHint=false, so the agent knows this may cause changes. However, the description adds no extra behavioral context such as potential side effects, authentication requirements, rate limits, or data that could be affected. It merely restates the 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 a single concise sentence with no filler or repetition. It is appropriately front-loaded and easy to parse, though it omits essential usage context that would make it more useful.

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 destructive, open-world tool with a nested schema and no output schema, the description is severely under-specified. It does not explain what the function returns, how errors are handled, or in what circumstances to choose this over sibling tools. The description alone would leave an agent uncertain about side effects and expected results.

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 provides descriptions for harRequest and its nested fields (url, method, headers, postData, queryString). The tool description adds no additional parameter semantics, so it relies entirely on the schema. Baseline 3 applies due to high schema description coverage.

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 action ('Executes an API request') and the resource ('a given HAR request object'). It distinguishes itself from sibling tools focused on retrieving or searching endpoints, though it doesn't explicitly name an alternative.

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

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

No guidance is provided on when to use this tool versus siblings like get-endpoint or search-endpoints. There are no stated prerequisites, exclusions, or example scenarios, leaving the agent to infer usage from the tool name 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?

Annotations declare readOnlyHint: true and openWorldHint: false, so the safety profile is already known. The description adds that the details include 'security schemes and servers', which is helpful return-content context, but it does not disclose additional behavioral traits like permissions, error handling, or side effects. With annotations covering the core safety aspect, 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?

The description is a single, front-loaded sentence that directly states the tool's purpose and key return elements. No unnecessary words, and every part is informative. This is a model of conciseness.

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

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

For a simple read-only tool with two well-described parameters and no output schema, the description provides enough context: it names the resource type (endpoint), the action (get details), and specific scopes (security schemes and servers). Combined with annotations for safety and schema for parameters, it is sufficiently complete for an agent to invoke correctly, though return format is not detailed.

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 provides full descriptions for both 'path' and 'method' (100% coverage). The tool description does not add any further meaning to the parameters, but the schema already does the heavy lifting, so a 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's function: 'Gets detailed information about a specific API endpoint'. The verb 'Gets' indicates a read operation, and the resource is precisely the endpoint details. This distinguishes it from sibling tools like list-endpoints (which lists endpoints) and search-endpoints (which searches), making the purpose 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?

The description implies the tool should be used when detailed information about a specific endpoint is needed, but it does not explicitly contrast with alternatives or state when not to use it. No exclusions or alternative tool names are mentioned, so guidance is limited to contextual 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=true, so the read-only nature is covered. The description adds that results are organized by path and include methods and summaries, which is useful but does not disclose potential large result sets or any ordering guarantees. Since the schema has no parameters, the description shares the burden of explaining behavior, but the added detail is modest.

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 exactly two sentences, front-loaded with the main purpose, and contains no fluff. Every phrase earns its place by specifying scope, content, and downstream usage.

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 list tool with no parameters and no output schema, the description adequately conveys what is returned (paths, methods, summaries) and how to use the results (feed into get-endpoint). It does not detail the summary format or mention size limits, but given the low complexity, 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?

With zero parameters, the schema coverage is trivially 100%. The description needs no parameter explanations, and the baseline for zero parameters is 4. The description adds no unnecessary parameter information.

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 'Lists all API paths and their HTTP methods with summaries, organized by path.' This is a specific verb (list) with a specific resource (all API endpoints) and clearly differentiates from siblings like 'get-endpoint' (singular) and 'search-endpoints' (filtered).

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 context for use by noting that results can be passed into 'get-endpoint', which implies a workflow for exploring endpoints. However, it does not explicitly contrast this with 'search-endpoints' or when to choose one over the other, 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 description claims a financial transaction ('pay-per-call USDC') while annotations declare readOnlyHint: true, implying no side effects. This is a direct contradiction. The annotation's read-only hint would mislead an agent into thinking no payment occurs, conflicting with the clear payment intent.

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 sentence, front-loaded with the usage condition, and every clause adds value. No redundancy or 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?

The description lacks critical context: it does not state what the tool returns after payment (no output schema exists), nor how the tool knows which endpoint to pay for given zero parameters. An agent cannot determine the next step after calling this tool. The contradiction with readOnlyHint further degrades completeness.

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?

There are zero parameters, and the schema coverage is 100% (empty schema). The description does not need to explain parameter syntax, but it references 'the same endpoint' without clarifying how that endpoint is identified given the absence of parameters, which is a minor gap. Baseline for 0 params is 4.

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 function: accessing Vybe endpoints via x402 pay-per-call USDC. It uses a specific verb ('use this to access') and a distinct mechanism (x402 pay-per-call), which differentiates it from sibling tools like execute-request or get-endpoint.

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 explicitly states when to use the tool: 'Before calling any Vybe endpoint without an API key', with examples (AI agent, throwaway script, premium-only path). It implicitly covers when not to use it (when you have an API key) by specifying the condition.

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 the description adds useful scope context (searches through paths, operations, and parameters) and the behavioral trait that results are compatible with get-endpoint. This goes beyond the annotations without contradicting them.

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 sentences that front-load the purpose and then provide usage guidance. No fluff, every sentence 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 simple single-parameter search tool with readOnlyHint and a clear handoff to get-endpoint, the description is adequately complete. It does not specify the return format, but the mention of passing results to get-endpoint implies a structure, and no output schema is expected for such a discovery tool.

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 single parameter 'pattern', and the description's mention of 'search keywords' aligns with but does not elaborate beyond the schema. The schema already documents case-insensitivity, so no additional semantic value is provided 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?

Description uses a specific verb ('Performs a deep search') and identifies the resource ('API endpoints') and scope ('paths, operations, and parameters'). It clearly differentiates from sibling tools like list-endpoints (which likely enumerates) and get-endpoint (which retrieves a single endpoint).

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?

States when to use the tool ('to find specific API capabilities, required parameters, or data models based on search keywords') and provides a natural follow-up action ('Results can be passed directly into get-endpoint'). It lacks explicit exclusions or alternatives, but the use case is clear enough for an agent to distinguish from sibling tools.

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