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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is covered. The description adds the useful detail that results include a frozen flag and subscription state, but nothing about auth, rate limits, or freshness.

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?

A single compact sentence with no filler, and the most important payload (remaining traffic) is front-loaded. Slightly list-like but 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?

An output schema exists, so return-value documentation is not required, and the description covers the conceptual payload. However, for a query tool sitting among several traffic-related siblings it gives no routing context, leaving a meaningful 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 takes zero parameters, so there is nothing for the description to disambiguate. Baseline 4 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?

Names the concrete outputs (remaining traffic in bytes, subscription status, frozen flag), so an agent knows what resource it reports on. It doesn't differentiate itself from siblings like traffic_stats, so it falls short of a 5.

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?

There is no guidance on when to call this versus traffic_stats or other siblings, and no stated preconditions. Usage must be inferred entirely from the description's content.

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, openWorldHint=true, destructiveHint=false, so the safety profile is covered. The description adds real value beyond that: it discloses that no traffic traverses the tunnel, that the return includes gateway status, exit IP (conditionally), and connection duration, and warns that a 407 may indicate a bad parameter rather than bad credentials. That last point is a non-obvious behavioral caveat.

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 action, followed by the traffic/return behavior and the diagnostic caveat. 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?

An output schema exists, so return-value detail is not strictly required, and the description still helpfully previews what comes back. The significant gap is the seven completely undocumented optional parameters for a tool that is parameter-sensitive (per the 407 note). An agent could call it, but not confidently steer 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?

Schema description coverage is 0% across 7 parameters (isp, ttl, city, filter, region, country, session_id), so the description carries the full burden and largely fails. The only nod to parameters is 'A 407 can mean a wrong parameter value,' which hints they affect routing/auth but explains none of their meaning, formats, or interactions.

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 and resource: 'Open one connection through the proxy and report the result.' Combined with the second sentence ('Sends no traffic through the tunnel'), the scope is clear and distinguishable from sibling tools like proxy_url or traffic_stats. It doesn't explicitly name a sibling to differentiate, which keeps it out of the top band.

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 line 'Sends no traffic through the tunnel' implies this is a lightweight connectivity/diagnostic check rather than a data-moving call, which is useful implied usage. However, there is no explicit statement of when to prefer this over proxy_url, list_locations, or account_status, and no 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 cover the safety profile (readOnlyHint=true, openWorldHint=true, destructiveHint=false), so the bar is lower, and the description adds genuinely useful behavior: the 100-row cap and the next_offset/offset continuation loop. It does not mention auth, rate limits, or errors beyond pagination.

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 purpose before the parameter rules and pagination mechanics. Nearly every clause earns its place, though the pagination sentence is slightly terse relative to its importance.

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?

An output schema exists, so return values needn't be explained, and the description still helpfully notes next_offset. For a 6-parameter tool it is largely complete, but the omission of limit and connection_type leaves a small 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?

Schema description coverage is 0%, so the description must carry the load. It explains the meaning of country_code and region_code per kind and the offset continuation, but never mentions limit or connection_type (an enum with residential/mobile), leaving two parameters undocumented.

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+resource ('List locations available for targeting') and immediately frames the purpose: producing the codes that proxy_url consumes. This explicitly ties it to the sibling proxy_url and distinguishes it from unrelated siblings like traffic_stats or top_domains.

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?

Gives hierarchy-aware guidance: 'regions need country_code; cities and isps can be narrowed by country_code and region_code.' This tells the agent which parameters matter for which kind. It stops short of naming alternative tools or stating when not to call it, so it lands at 4 rather than 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?

Annotations already declare readOnlyHint=true, openWorldHint=true, destructiveHint=false, so the safety profile is covered. The description adds meaningful context beyond that: the pagination contract (start at 1, resume via next_page, empty result past the end) and the security-relevant guarantee that no passwords are returned.

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?

Very short and front-loaded: the resource and payload come first, then the pagination behavior. Both sentences carry information, though the stray line break mid-sentence is cosmetic rather than wasteful.

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?

An output schema exists, so return values need not be explained, and the description covers the one non-obvious interaction detail an agent needs (how to paginate). For a single-optional-parameter read tool, this is close to complete, with only sibling differentiation left implicit.

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 0% and there is one parameter (page), so the description carries some burden. 'Paged from page 1' documents the starting convention, which is the only real semantic addition; it doesn't clarify whether page is 1-based offset semantics beyond the default, and next_page is referenced without being a declared input.

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?

Identifies the specific resource (sub-users of the account) and the payload (traffic usage and limits), and adds the exclusion 'No passwords.' The verb is only implied by the tool name, but the resource is clearly distinct from siblings like traffic_stats, top_domains, and proxy_url.

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?

Gives explicit operational guidance for pagination: start at page 1, and when next_page is returned call again with it; a page past the end comes back empty. However, it offers no guidance on when to prefer this tool over siblings such as traffic_stats, which is implied but not stated.

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 readOnly/destructive=false, so the description's added value is real: it explains sticky-vs-rotating exit IP behavior tied to session_id/ttl, and discloses that the password is a placeholder unless the server allows revealing it. That is meaningful behavioral 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?

Front-loads the core purpose, then layers parameter semantics compactly with no filler. Slightly dense but 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?

An output schema exists so return values need no explanation, and the description covers behavior and parameter meaning well. It omits that all 8 parameters are optional and the protocol parameter's meaning, which are minor gaps.

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 0%, so the description carries the full burden and largely meets it: it documents session_id, ttl (with example formats), country format, region/city/isp sourcing from list_locations, and filter. Only protocol is left unexplained, though its enum and default make it self-evident.

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+resource ('Build a NodeMaven proxy string'), which is distinguishable from siblings like check_proxy and list_locations. It does not explicitly name those siblings to route the agent, but the purpose is 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?

It implies usage by pointing to list_locations for country/region/city/isp codes and explaining the session_id/ttl tradeoff, but it never says when to use this tool versus check_proxy or account_status, nor states prerequisites or when-not-to-use.

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 and openWorldHint=true, so the safety profile is covered. The description adds the default time window and the non-ISO date format constraint, which is genuine behavioral context, but says nothing about pagination, result size, or how limit interacts with the ranking.

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 tight sentences: the first front-loads what the tool returns, the second covers the time-window inputs and default. No filler, though the trailing blank line and the 'Pass period, or...' phrasing is slightly terse rather than polished.

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?

An output schema exists, so return values need not be described, and the time-window inputs are covered. Still missing for a 4-parameter tool: the meaning of limit, the enum semantics of period, and precedence when both period and start/end are supplied.

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 0%, so the description carries the burden and it does explain period, start and end, including the dd-mm-yyyy format warning. But it ignores the limit parameter entirely and never enumerates the period values (today, hours24) that the schema only exposes as a bare enum.

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 the resource clearly ('Domains reached through the proxy') and the ordering/aggregation ('largest traffic first, with bytes and request counts'), so the agent knows exactly what comes back. It does not explicitly differentiate itself from siblings like traffic_stats or proxy_url, but the scope is 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?

It explains how to supply a time window (period, or start/end as dd-mm-yyyy) and notes the default is today, which is useful call-site guidance. However, it never says when to choose this tool over traffic_stats or proxy_url, and it doesn't say whether period and start/end are mutually exclusive.

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 and openWorldHint=true, so the safety profile is covered. The description adds genuinely useful behavioral context: the output is 'parallel labels and data arrays' and dates must be dd-mm-yyyy rather than ISO. This is a real addition beyond annotations, though it does not touch auth, rate limits or error 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?

Two short sentences with no filler; the purpose is front-loaded before the parameter notes. The 'parallel labels and data arrays' phrasing is slightly cryptic, which costs a point.

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?

An output schema exists, so return values need not be described. With three parameters at 0% schema coverage, the description covers the date format and default but leaves the period enum values and start/end pairing rules to inference, which is a clear gap for an agent invoking the 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 description coverage is 0%, so the description must carry the parameter burden. It documents the start/end format ('dd-mm-yyyy (not ISO)') and the default ('today'), but never names the allowed period values (today, hours24) or notes that start/end are the alternative to period. It compensates partially, not fully.

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 resource and scope: 'Traffic used over time, as parallel labels and data arrays.' An agent can tell this returns time-series bandwidth data. However, it does not distinguish this from siblings like account_status or top_domains, which may also touch usage figures, so it falls short of a 5.

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 only usage direction is parameter-shape guidance ('Pass period, or start and end... Defaults to today'). There is no statement of when this tool is the right choice versus alternatives, nor any when-not condition, so the guidance dimension is largely unaddressed.

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