SF Muni Real-Time Transit

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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=true, and idempotentHint=true, covering safety and idempotency. The description adds context about what data is retrieved (alerts, detours, disruptions) but doesn't disclose additional behavioral traits like rate limits, data freshness, or error handling. With annotations providing core safety info, a 3 is appropriate as the description adds some value without contradiction.

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 appropriately sized and front-loaded, with the main purpose stated first and parameter details in a separate 'Args' section. It avoids unnecessary words, though the parameter note could be integrated more seamlessly. Overall, it's efficient with minimal waste.

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 low complexity (1 optional parameter, no output schema) and rich annotations, the description is adequate but incomplete. It covers the basic purpose and parameter but lacks usage guidelines and detailed behavioral context. For a simple read-only tool, it's minimally viable but has clear gaps in guiding the 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?

Schema description coverage is 100%, with the parameter 'operator_id' documented as 'Operator ID (default SF).' The description adds minimal semantics by noting it's 'Optional (default 'SF')' but doesn't explain what 'SF' means or provide examples. Since the schema already does the heavy lifting, baseline 3 is correct.

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: 'Get current Muni service alerts, detours, and disruptions.' It specifies the verb 'Get' and the resource 'Muni service alerts, detours, and disruptions.' However, it doesn't explicitly differentiate from sibling tools like 'muni_departures' or 'muni_schedule,' which might also provide related information, so it doesn't reach the highest score.

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 doesn't mention sibling tools like 'muni_departures' or 'muni_schedule,' nor does it specify contexts or exclusions for usage. This leaves the agent without clear direction on tool 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?

Annotations already provide strong behavioral hints (readOnlyHint: true, destructiveHint: false, openWorldHint: true, idempotentHint: true), indicating this is a safe, read-only, idempotent query. The description adds minimal context beyond this, mentioning 'real-time' which implies freshness but doesn't specify rate limits, data sources, or error conditions. No contradiction with annotations exists.

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 and well-structured: a single clear purpose statement followed by brief parameter notes. Every sentence adds value without redundancy, and it's front-loaded with the core functionality. No wasted words or unnecessary elaboration.

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 moderate complexity (2 parameters, no output schema) and rich annotations covering safety and behavior, the description is reasonably complete. It clearly states what the tool does and provides basic parameter guidance. However, it could better address when to use versus siblings and add more behavioral context like data freshness or limitations to compensate for the lack of output schema.

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%, with both parameters (stop_code and operator_id) well-documented in the schema. The description adds the '5-digit stop code' detail for stop_code and clarifies operator_id as 'Optional (default 'SF')', which slightly reinforces but doesn't significantly expand beyond schema information. Baseline 3 is appropriate given high 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 purpose with a specific verb ('Get'), resource ('real-time departure predictions'), and target ('for a Muni stop'). It distinguishes this from sibling tools like muni_alerts, muni_schedule, or muni_vehicles by focusing specifically on departure predictions rather than alerts, schedules, or vehicle locations.

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 context by specifying 'real-time departure predictions,' suggesting it should be used when current departure times are needed rather than static schedules. However, it doesn't explicitly state when to use this tool versus alternatives like muni_schedule (for scheduled departures) or muni_vehicles (for vehicle tracking), nor does it mention any prerequisites or 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?

Annotations provide readOnlyHint=true, destructiveHint=false, openWorldHint=true, and idempotentHint=true, indicating safe, non-destructive, cacheable operations. The description adds context by specifying that it includes 'stops' in the details, which is useful behavioral information not covered by annotations. It does not contradict annotations, as 'Get' aligns with read-only 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 front-loaded with the core purpose in the first sentence, followed by a concise Args section. Every sentence earns its place by providing essential information without waste, making it efficient and 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?

Given the tool's low complexity (2 parameters, no output schema), rich annotations (covering safety and behavior), and high schema coverage, the description is mostly complete. It specifies what details are included (stops) and provides parameter examples. However, it could improve by mentioning output format or limitations, but annotations help compensate.

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%, with clear descriptions for line_id and operator_id. The description adds minimal value beyond the schema by providing an example ('e.g. 'N', '14', '38R'') for line_id, which is helpful but not extensive. Since the schema already covers parameters well, the 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 clearly states the verb 'Get' and the resource 'details for a specific Muni line including stops', which is specific and distinguishes it from siblings like muni_alerts (alerts), muni_departures (real-time departures), and muni_routes (list of routes). It precisely defines what the tool does.

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 by specifying 'details for a specific Muni line', suggesting it's for retrieving information about a particular line rather than lists or real-time data. However, it does not explicitly state when to use this tool versus alternatives like muni_routes (which might list lines) or muni_map (which might show visual data), leaving some ambiguity.

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 cover key traits (read-only, open-world, idempotent, non-destructive), so the bar is lower. The description adds useful context: 'interactive' suggests user engagement, and 'real-time departures' hints at dynamic data retrieval. It doesn't contradict annotations and enhances understanding beyond structured fields.

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 front-loaded and efficient: two concise sentences that directly state the tool's function and interactive feature. Every sentence earns its place with no wasted words, making it easy for an agent to parse quickly.

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 low complexity (0 parameters, no output schema) and rich annotations, the description is adequate but has gaps. It explains what the tool does but lacks details on return values or error handling. With annotations covering safety, it's minimally viable but could be more complete for interactive use.

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 0 parameters and 100% schema description coverage, the baseline is high. The description doesn't need to explain parameters, and it adds value by describing the interactive map functionality, which compensates for the lack of parameter details. No parameters to document, so it's above 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 clearly states the tool's purpose: 'Open interactive Muni Metro map' specifies the verb (open) and resource (interactive map), and 'Click stops to see real-time departures' explains the interactive functionality. However, it doesn't explicitly differentiate from siblings like 'muni_routes' or 'muni_map' alternatives, keeping it from a perfect score.

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 such as 'muni_departures' or 'muni_routes'. It implies usage for map viewing and real-time data but lacks explicit when/when-not instructions or named alternatives, leaving the agent to infer 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?

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=true, and idempotentHint=true, covering safety and idempotency. The description adds no behavioral context beyond what annotations provide, such as rate limits, authentication needs, or pagination behavior, but doesn't 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 appropriately sized with two sentences: one stating the purpose and one explaining the parameter. It's front-loaded with the core functionality, though the parameter note could be integrated more seamlessly.

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 low complexity (one optional parameter), rich annotations covering safety and behavior, and no output schema, the description is minimally adequate. However, it lacks details on output format (e.g., list structure, fields) and doesn't leverage context to explain sibling tool distinctions, leaving gaps for agent usage.

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%, with the parameter 'operator_id' fully documented in the schema. The description repeats the default value ('SF') but adds no additional meaning, syntax, or format details beyond what the schema provides, meeting the baseline for high 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 verb ('List') and resource ('all SF Muni routes') with specific scope ('bus, rail, cable car'), making the purpose unambiguous. However, it doesn't explicitly differentiate from sibling tools like 'muni_line' or 'transit_operators', which might also list route-related information.

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 like 'muni_line' (which might get details for a specific route) or 'transit_operators' (which might list operators). It only includes a default parameter note, not usage context or 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?

Annotations already indicate read-only, non-destructive, idempotent, and open-world behavior. The description adds context by specifying it retrieves a 'timetable/schedule,' which implies static schedule data rather than real-time updates, but doesn't detail rate limits, auth needs, or exact return format. It aligns with annotations without contradiction.

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 front-loaded with the core purpose in the first sentence, followed by a concise Args section. Every sentence earns its place by clarifying parameters without redundancy, making it efficient and 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?

Given the tool's low complexity, rich annotations (covering safety and behavior), and 100% schema coverage, the description is mostly complete. However, without an output schema, it doesn't explain return values (e.g., schedule format), leaving a minor gap in contextual 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?

Schema description coverage is 100%, with clear parameter documentation. The description adds minimal value beyond the schema, providing examples for line_id (e.g., 'N', '14', '38R') and noting operator_id is optional with a default. This meets the baseline for high 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 purpose with a specific verb ('Get') and resource ('timetable/schedule for a specific Muni line'), distinguishing it from siblings like muni_alerts (alerts), muni_departures (real-time departures), and muni_routes (route lists). It precisely defines what information is retrieved.

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 by specifying it's for a 'specific Muni line,' but it doesn't explicitly state when to use this tool versus alternatives like muni_departures (for real-time data) or muni_routes (for route metadata). No exclusions or clear alternatives are provided, leaving some ambiguity.

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 provide key behavioral hints: readOnlyHint=true, destructiveHint=false, openWorldHint=true, and idempotentHint=true. The description adds minimal context by specifying 'real-time' data, which implies freshness but doesn't detail rate limits, data format, or authentication needs. It doesn't contradict annotations, so it earns a baseline score for adding some value beyond structured fields.

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 front-loaded with the core purpose in the first sentence, followed by a brief Args section. It's efficient with zero waste, but the Args section slightly duplicates schema information without adding value, preventing a perfect score.

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 doesn't explain return values (e.g., data format, fields). Annotations cover safety and idempotency, but for a real-time data tool, more context on freshness, limitations, or error handling would be helpful. It's adequate given the simple parameter setup but lacks depth for full 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?

The input schema has 100% description coverage, with operator_id documented as 'Operator ID (default SF).' The description repeats this in the Args section but adds no additional meaning, such as what operator IDs are valid or how they affect results. Given the high schema coverage, the 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 clearly states the tool's purpose: 'Get real-time GPS positions of Muni vehicles.' This specifies the verb ('Get'), resource ('GPS positions of Muni vehicles'), and scope ('real-time'). However, it doesn't explicitly differentiate from siblings like muni_map or muni_departures, which might also involve vehicle data, so it doesn't reach the highest score.

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. With siblings like muni_map (which might show vehicle positions on a map) and muni_departures (which could include vehicle timing), there's no indication of context, exclusions, or preferred use cases, leaving the agent to infer usage.

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 provide readOnlyHint=true, destructiveHint=false, openWorldHint=true, and idempotentHint=true, covering safety and idempotency. The description adds value by specifying the scope ('all transit operators') and examples, which helps the agent understand the breadth of data returned, though it doesn't disclose additional behavioral traits like rate limits or response format.

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, efficient sentence that front-loads the purpose ('List all transit operators') and provides helpful examples without any wasted words. It's appropriately sized and structured for a simple 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?

Given the tool's simplicity (0 parameters, no output schema) and rich annotations, the description is complete enough by stating what it does and providing examples. However, it could slightly improve by mentioning the lack of filtering or the response structure, though annotations cover key behavioral aspects.

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 0 parameters, and schema description coverage is 100%, so no parameter documentation is needed. The description appropriately focuses on the tool's purpose without redundant parameter info, earning a high baseline score for this dimension.

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 'List' and the resource 'transit operators available in the 511 API', with specific examples (BART, Muni, Caltrain, AC Transit) that help distinguish it from sibling tools focused on Muni-specific operations. It's specific and immediately tells what the tool does.

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 context by mentioning '511 API' and listing examples, which suggests this tool is for retrieving a broad set of operators rather than Muni-specific data. However, it does not explicitly state when to use this vs. the sibling tools (e.g., for general operator info vs. Muni-specific details), so it lacks explicit alternatives or exclusions.

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