Telnyx

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint false. The description adds the purpose of the returned schema (for invocation) but does not disclose additional behavioral details such as error cases or output format specifics. With annotations covering the safety profile, this is adequate but minimal.

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 sentences: the first front-loads the purpose and the second provides practical usage. No redundant wording.

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, one-parameter tool with strong annotations, the description is complete. It explains what the tool returns and how to use it in conjunction with invoke_api_endpoint, covering the intended workflow.

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 'endpoint' has 100% schema description coverage, and the tool description does not add any meaning beyond what the schema already provides. 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 'Get the schema for an endpoint in the Telnyx TypeScript API' with a specific verb and resource, and explicitly references the invoke_api_endpoint tool, distinguishing it from sibling tools like list_api_endpoints and invoke_api_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 gives clear usage context by stating the schema can be used to invoke an endpoint with invoke_api_endpoint. However, it does not explicitly mention when not to use this tool or compare it with list_api_endpoints.

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 no behavioral context beyond the annotations. It does not mention side effects, authentication needs, rate limits, or expected outcomes. The annotations already indicate destructive/read-write behavior, but the description does not elaborate on implications for the agent.

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 sentences that convey purpose and usage guidance without any fluff. It is front-loaded with the primary action and immediately follows with helpful pointers.

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 adequate for a generic invocation tool, especially with the reference to helper tools for endpoint discovery and schema. However, it does not mention response handling, error conditions, or the need for authentication, which would make it more complete given the tool's broad scope.

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 fully describes both parameters (endpoint_name and args), including the need for args to match the endpoint schema. The description does not add extra semantic detail but references the schema tool, which is enough to satisfy a baseline score given 100% schema 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 tool's function with a specific verb ('Invoke') and resource ('endpoint in the Telnyx TypeScript API'). It also distinguishes itself from sibling tools like list_api_endpoints and get_api_endpoint_schema, which serve discovery purposes.

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 explicit guidance by pointing to list_api_endpoints for obtaining the endpoint list and get_api_endpoint_schema for the schema, implying that invoke_api_endpoint is used after these. However, it does not state when not to use this tool, so it falls short of a perfect score.

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 establish readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is known. The description adds no further behavioral context such as pagination, authentication needs, or return format. It does not contradict 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 single, front-loaded sentence with no filler or redundancy. It efficiently communicates the core function without extra words.

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 one optional parameter, a clear purpose, and thorough annotations, the description is largely sufficient. However, it does not specify what fields are returned or the nature of the search (e.g., partial match), which would be helpful given no output schema. This is a minor gap for a simple list 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% because the only parameter (search_query) is fully described in the input schema. The tool description itself does not add any parameter meaning beyond the schema, so the baseline score of 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 uses a specific verb ('List or search') and a clear resource ('all endpoints in the Telnyx TypeScript API'), which precisely states what the tool does. It is clearly distinct from siblings like get_api_endpoint_schema, which retrieves a schema for a specific 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?

No explicit when-to-use or alternative guidance is provided. The description implies usage for discovering endpoints, but it does not mention when to choose this over get_api_endpoint_schema or invoke_api_endpoint. Usage is only implied through the tool's purpose.

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

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

The annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, which fully cover the safety profile. The description adds the workflow context but does not disclose any further behavioral traits (e.g., what happens upon opening, whether it returns data, or any side effects). It does not contradict 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?

The description is a single, front-loaded sentence with no filler. It efficiently conveys the action, resource, and purpose without redundancy or unnecessary 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?

Given the tool's simplicity (0 required params, one no-op optional param) and the comprehensive annotations, the description covers the essential 'what' and 'why.' However, it could slightly improve by noting that the app is opened for later user interaction rather than performing actions itself, but this is a minor gap for a low-complexity 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?

The input schema has 100% coverage: it fully describes the single 'action' parameter with an enum and explanation. The description adds no additional parameter information, so it does not go beyond the schema. Baseline 3 is appropriate given the schema already does the heavy lifting.

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 verb 'Open', the resource 'Telnyx Number Intelligence MCP App', and its purpose for 'phone number lookup, validation, and enrichment workflows.' This distinguishes it from sibling openers like 'open_usage_cost_explorer' and 'open_voice_monitor' by specifying a unique app and workflow.

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 usage contexts via 'phone number lookup, validation, and enrichment workflows,' but it does not explicitly mention when-to-use vs alternatives or exclusions. There is no naming of alternative tools or guidance on choosing this over the sibling openers, so usage guidance is only implied.

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, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds no extra behavioral details beyond the purpose (opening an app), which is consistent with annotations and not contradictory.

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 one short sentence that conveys the tool's purpose without unnecessary words. It is front-loaded and 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 simple app-opening tool with strong annotations and full schema coverage, the description is sufficient. It does not explain return values, but no output schema exists and the open action implies launching a UI, which is clear enough.

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

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

The single parameter 'action' is fully documented in the schema with enum and description, including its optional no-op nature. The description does not need to add more, as schema coverage is 100%.

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 uses a specific verb ('open') and names the exact resource ('Telnyx Usage & Cost Explorer MCP App'), making it distinct from sibling open tools like open_number_intelligence and open_voice_monitor. It clearly states the tool's function with no ambiguity.

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 phrase 'for usage and cost analysis' provides clear context for when this tool is appropriate. It does not explicitly mention when not to use it or alternatives, but the context is enough for an agent to decide.

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, idempotentHint=true, and destructiveHint=false. The description's 'open' and 'observing' align with these but add no further behavioral traits like authentication needs, return format, or UI behavior. It adds context that the app is for voice traffic, which is purpose rather than 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 of 14 words, front-loading the verb 'Open' and the specific app name. Every word contributes to clarity, with no filler or repetition.

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 low-complexity tool with one optional no-op parameter and no output schema, the description fully conveys its purpose and context. It distinguishes from siblings and aligns with annotations, so nothing critical is missing.

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

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

The schema provides 100% coverage for the single optional parameter 'action', including its enum, default, and description. The tool description does not mention parameters, but the schema handles it fully, so 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 uses 'Open' as a specific verb, names the exact resource 'Telnyx Voice Monitor MCP App', and states the purpose 'observing and troubleshooting voice traffic'. This clearly differentiates it from siblings like open_number_intelligence and open_usage_cost_explorer.

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 clearly implies the tool is for voice traffic monitoring/troubleshooting, giving a clear context for when to use it. However, it does not explicitly mention when not to use it or name alternative tools, so it lacks exclusions.

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