FetchFox

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

The description says "List comments," which asserts a read-only retrieval operation, while the annotations declare readOnlyHint=false (i.e., the tool may modify its environment). That is a direct contradiction in the read/write dimension, and the description adds no other behavioral context (rate limits, auth, pagination 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?

It is a single front-loaded sentence with zero filler, so nothing wastes the agent's attention. The flip side is that at one clause it is arguably under-specified for a tool with cursor pagination, keeping it just below 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?

For a simple three-parameter listing tool with no output schema this is minimally adequate: the schema covers all inputs and there are no return values to explain. However, it omits any note on pagination flow (reuse cursor, omit on first call) or that only public content is supported, which the annotations' contradictory readOnlyHint makes more consequential.

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 url, limit, and cursor are all documented in the schema itself (public URL, max items with "collection can return fewer," opaque cursor). The description adds no meaning beyond that, which is the expected baseline when the schema 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 names a specific verb and resource ("List comments") and scopes it to a Facebook post or video, which separates it from the instagram_comments sibling by platform and by target object. It is clear but never explicitly contrasts itself with the other *_comments / stats tools in the sibling set, so it stops 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 use this tool versus instagram_comments, instagram_stats, or the other siblings, and no mention of prerequisites such as the post being public. The only usage signal is the implicit platform/object scoping in the single sentence, which the agent must infer.

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 supply readOnlyHint=false, openWorldHint=true, and destructiveHint=false, but the description adds no behavioral context such as rate limits, whether the profile must be public, how far back "recent" reaches, or how pagination behaves across calls. For a scraping-style open-world tool, the description carries little of the extra burden.

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 well-formed sentence with the resource and scope front-loaded and no filler. It is efficient, though arguably too terse given the surrounding gaps.

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 and no explanation of what a returned "post" contains (media, caption, metrics, timestamp), an agent cannot anticipate result shape or how to iterate with the cursor. For a list/pagination tool with three parameters and no output schema, the description should do more than restate the name.

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 url, limit, and cursor are already fully documented in the schema (including the cursor's opaque nature and the limit's "may return fewer" caveat). The description adds no parameter meaning beyond that, which is the expected baseline when the schema 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 names a specific verb ("List") and resource ("recent posts") scoped to an Instagram profile URL, which clearly separates it from siblings like instagram_channel_reels and instagram_channel_stats. It stops short of explicitly naming those alternatives, so an agent must infer the boundary from the resource noun alone.

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 choose this tool over instagram_channel_reels, instagram_channel_stats, or instagram_comments, even though they all operate on the same Instagram profile target. No prerequisites (e.g., profile must be public) or exclusions are 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 openWorldHint, destructiveHint=false and non-idempotency; the description adds nothing on top — no rate limits, no pagination behavior beyond what the schema's cursor field states, no note on what happens with private/nonexistent profiles. It also says 'List', which reads as a pure read, while readOnlyHint=false implies the tool may not be side-effect free; this tension is left unexplained.

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?

One front-loaded sentence with zero filler; the resource and scope come first. It is efficient, though the extreme brevity is part of why usage and behavioral gaps exist.

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 should describe what a reel entry contains and how pagination/cursor results behave, but it says nothing about the return shape. Combined with missing sibling differentiation and no edge-case handling (private profiles, invalid URLs), it is thin for the tool's 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?

Schema description coverage is 100%, so url, limit (with max/exclusiveMinimum) and cursor are already fully documented, including the 'collection can return fewer' caveat. The description only echoes the url concept as 'profile URL' and adds no format or syntax detail, so the 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?

Specific verb (List) plus resource (reels) plus scope (recent, from an Instagram profile URL). The word 'reels' implicitly separates it from the sibling instagram_channel_posts, but the description never names or contrasts that sibling explicitly, 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?

No when-to-use or when-not-to-use guidance, no prerequisites (public profile required, auth needs), and no routing between this and instagram_channel_posts or instagram_comments. The agent must infer everything from the name.

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 the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=true), so the bar is lower, but the description adds no behavior beyond the field list: no auth/cost requirements, rate limits, private-profile failure modes, or explanation of why a 'get' is not read-only.

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?

One front-loaded sentence with the verb and resource first and a compact parenthetical field list; nothing is filler and nothing needed is buried.

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 one-parameter read tool with no output schema, listing the returned fields partially compensates for the missing output contract. However, error behavior, profile visibility requirements, and any usage routing are absent, leaving it only marginally complete.

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?

Single parameter with 100% schema description coverage ('Public instagram channel/profile URL'), so the schema already carries the meaning. The description adds no additional constraint, such as whether the URL must be public or what form it takes.

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 ('Get channel-level stats for an Instagram profile') and enumerates the returned fields, which cleanly separates it from instagram_channel_posts and instagram_channel_reels. It stops short of explicitly naming which sibling to use for post/reel-level data, so it is clear but not fully self-differentiating.

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 when-to-use guidance, no prerequisites, and no mention of the alternatives (instagram_stats vs the channel_* scrapers). The only hint of scope is 'channel-level,' which the agent must interpret on its own.

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?

With annotations only declaring safety/idempotency flags, the description carries the important behavioral burden and does it well: partial vs. exhausted collection, the fact that hasMore=false does not prove completeness, that exhausted means pagination ended rather than hidden comments/replies being captured, and that conclusions must be scoped to returned comments. This is material operational context an agent could not infer from the 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?

Purpose is front-loaded in one sentence, followed by tightly packed caveats about result interpretation. Every sentence carries information, though the three consecutive incompleteness caveats could be consolidated slightly.

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 paginated collection tool with no output schema, the description names the key result fields (collectionStatus, stopReason, hasMore) and how to interpret them, which is exactly the gap the schema cannot fill. Missing are auth/rate-limit expectations and the shape of individual comment objects, but nothing essential to correct invocation is absent.

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% (url, limit, cursor, sortBy all documented), so the baseline is 3. The description adds only indirect meaning — that a cursor is a "safe cursor" and that stopping is not evidence of completeness — without clarifying limit or sortBy behavior beyond the schema.

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 first sentence names a specific verb and resource ("List comments on an Instagram post or reel") and its Instagram scope implicitly separates it from the facebook_comments sibling. It stops short of an explicit contrast with the nearest alternative, but the purpose is unambiguous and front-loaded.

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?

"Check collectionStatus ... and stopReason before analysis" gives real guidance on how to consume results, but there is no statement of when to choose this tool over siblings (e.g. facebook_comments or instagram_stats) and no prerequisite/auth context. Usage is implied rather than spelled out.

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?

With the output schema absent, the description carries return-value behavior and does it well: it explicitly warns 'Never treat null as zero' and maps each nullable field (views, shares, duration) to the condition that nulls it, which prevents a real agent error. It does not explain why the tool is marked readOnlyHint=false and idempotentHint=false despite being described as a 'Get', leaving that tension unaddressed.

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?

Purpose leads, then the caveat sentences are packed with no filler; each sentence carries a distinct fact. Slightly list-like in the null enumeration, but appropriate for the warning it delivers.

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 2-parameter, no-output-schema tool, the description covers the return surface adequately (metadata, CDN URL, null semantics) so an agent won't misread stats. It stops short of describing what 'metadata' includes, which is the remaining gap with no output schema to fall back on.

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%, so both parameters are already documented; the description restates them at a similar level of detail ('strict count recovery' adds only a hint about the strictness/latency tradeoff already implied by 'defaults to false for immediate media delivery'). Baseline 3 applies since the schema 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?

States a specific verb and resource ('Get metadata and a video CDN URL for an Instagram post or reel') with a clear scope: single post/reel. This implicitly separates it from channel-level siblings like instagram_channel_stats and instagram_channel_reels, but never names or contrasts them explicitly.

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 requireViews guidance ('requireViews=true enables strict count recovery') is genuine usage advice for one parameter, but there is no when-to-use guidance relative to the siblings (e.g., vs. instagram_channel_stats for channel-level data) and no stated prerequisites for the URL.

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 disclose openWorldHint=true, destructiveHint=false and idempotentHint=false, so the safety profile is largely covered. The description usefully adds the 100-video ceiling, the metadata payload, and cursor-based pagination, but says nothing about auth requirements, rate limits, or the scope of the external fetch. Note a mild tension: the description depicts a pure read while readOnlyHint is false.

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 tightly written sentences that are front-loaded with the core capability, followed by return payload and pagination. The field enumeration is long but earns its place given there is no output schema.

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 carries the return-value burden and does so explicitly by listing the metadata fields. Combined with schema-documented parameters and annotations covering the safety profile, an agent has nearly everything needed, missing only auth/rate-limit 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?

Schema description coverage is 100%, so url, limit and cursor are fully documented in the schema, giving a baseline of 3. The description's 'Supports pagination via the cursor field' and 'up to 100 videos' essentially restate the schema's cursor and maximum rather than adding new syntax or format detail.

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 ('Get a list of recent videos from a TikTok channel') and enumerates the returned fields, so the agent knows exactly what it gets. It does not explicitly distinguish itself from siblings like tiktok_search or tiktok_stats, which the agent must infer from the name alone.

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 is only implied by 'recent videos from a TikTok channel' — there is no statement of when to prefer this over tiktok_search or tiktok_stats, and no prerequisites or exclusions. Adequate for a simple fetch, but the routing decision is left entirely 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 supply the safety profile (destructiveHint=false, openWorldHint=true), so the bar is lower, and the description adds real value by explaining that includeShortShareUrl enriches each comment with a short link or null while the existing shareUrl is retained. It does not address pagination behavior or the odd readOnlyHint=false on what reads as a listing operation.

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, no filler, and the core purpose is front-loaded before the optional enrichment detail. The second sentence is dense but each clause carries information about the parameter's output effect.

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?

Without an output schema, the description carries more of the burden of explaining what comes back; it only hints at return shape via the shareUrl/shortShareUrl detail and says nothing about the comment record structure beyond that. Annotations cover safety, so the remaining gap is modest but real.

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%, so the baseline is 3, but the description goes beyond the schema by explaining the effect of includeShortShareUrl on the returned per-comment data (short link or null, existing shareUrl retained) and framing it as an additive enrichment rather than a replacement. That is genuine semantic value on top of the schema text.

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 ('List comments on a TikTok video or photo post') and pins the platform, which is the main axis separating it from facebook_comments, instagram_comments, and youtube_comments. It stops short of naming or contrasting any sibling directly, so it is clear but not fully differentiated.

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 statement of when to use this tool versus the sibling comment endpoints, nor any prerequisite or exclusion. The only conditional language ('Set includeShortShareUrl to...') is guidance on a parameter, not 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 disclose readOnlyHint=false, openWorldHint=true, idempotentHint=false, and destructiveHint=false, so the safety profile is covered. The description adds no further behavioral context—no pagination, rate limits, auth requirements, or return characteristics—despite the tool having no output schema.

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 front-loaded sentence with zero wasted words. It is appropriately sized for a minimal tool description.

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 search tool with four parameters, pagination cursor, regional filtering, and no output schema, the description is too thin. It does not explain what results look like, how to paginate using the cursor, or what the limit/country parameters do, leaving significant gaps for correct invocation.

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%, so all four parameters are documented in the schema itself. The description mentions 'query' but adds no syntax, default, or format details beyond what the schema already provides; baseline 3 applies when the schema 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 states a clear verb (search) and resource (TikTok videos), and 'by query' identifies the required input. However, it does not differentiate this tool from siblings like tiktok_channel_videos or tiktok_stats, so the agent gets no help disambiguating similar capabilities.

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 when-to-use or when-not-to-use guidance is provided. The description does not mention alternatives such as tiktok_channel_videos for channel-scoped content or tiktok_stats for metrics, leaving the agent to infer routing on its own.

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 openWorldHint=true, destructiveHint=false, and readOnlyHint=false. The description adds useful context by listing returned metrics, but does not disclose external API behavior, rate limits, authentication requirements, or error handling. It does not directly 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?

A single front-loaded sentence with zero waste. It starts with the verb and resource, then efficiently lists the returned fields.

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 tool with no output schema, the description identifies the scope and returned metrics. It is largely complete, though it could mention authentication or rate-limit expectations for the external TikTok API.

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 single required url parameter is already fully documented. The description does not add syntax, format, or validation details beyond what the schema provides, making the baseline 3 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?

States a specific verb (Get) and resource (engagement stats for a single TikTok video), and lists the returned metrics. It clearly scopes to a single video, distinguishing it from sibling channel tools, but does not explicitly name alternatives.

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 is implied by 'single TikTok video' and the required public URL, but there is no explicit when-to-use, when-not-to-use, or routing guidance against siblings such as tiktok_channel_videos or tiktok_search.

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 openWorldHint=true, destructiveHint=false and idempotentHint=false, lowering the bar; the description adds the useful scope constraint that results are channel-level and enumerates what comes back. It says nothing about authentication, quota/rate limits, or failure behavior for invalid or private URLs — notable for an open-world network call — and the retrieval verb ('Get') sits in mild tension with readOnlyHint=false, though that flag likely reflects external API side effects rather than a real mutation.

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 front-loaded sentence with no filler; the operation and its scope come first. 'Profile info' is slightly loose but does not undermine the sentence's efficiency.

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 carry return-value information, and it does by naming the four metric families the caller receives. For a single-parameter read tool with annotation coverage of the safety profile, that is close to complete; only edge-case behavior (private/handle-vs-URL input, errors) is unaddressed.

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?

Only one parameter and schema description coverage is 100%, so the schema alone documents the 'url' input. The description's field list ('subscribers, total views, video count, profile info') actually describes the response, not the input, adding no syntax or format detail beyond the schema — the 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?

States a specific verb and resource ('Get channel-level stats') plus the exact input domain ('for a YouTube channel URL'), and enumerates the returned fields, so it is clearly distinguishable from youtube_videos or youtube_search. It stops short of explicitly naming the closest sibling (youtube_stats) or clarifying whether that sibling covers video-level rather than channel-level metrics.

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 'channel-level stats ... for a YouTube channel URL' implies when this tool applies versus channel-agnostic siblings, but there is no explicit when-to-use or when-not-to-use statement. With youtube_stats and youtube_videos present in the sibling list, an agent gets no routing guidance for the ambiguous case.

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?

With annotations present (readOnlyHint=false, openWorldHint=true), the disclosure bar is lower, and the description usefully reveals the lack of cursor-based pagination. It does not explain rate limits, what happens on private/invalid videos, or the shape of comments 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?

Two tight sentences, front-loaded with the core action and followed by the key operational caveat. 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?

For a simple two-parameter read tool with full schema coverage and annotations, the definition covers what's needed to invoke it correctly. Only minor gaps remain around error behavior and comment fields, which an output schema would otherwise cover.

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%, so both parameters are already documented including the 1-100 range and default of 20. The description's note that limit bounds the returned sample and that there is no cursor adds modest value over the schema.

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 comments on a YouTube video") that is clearly distinct from the platform-specific comment siblings. However, it offers no further disambiguation beyond the platform implied by the name.

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?

Adds a useful practical note that limit bounds the sample because no pagination cursor exists, which implies usage for sampling rather than exhaustive retrieval. It never states when to prefer this over sibling comment tools or what prerequisites (e.g., public video) apply.

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 nothing behavioral beyond the annotations: no note on ranking, result caps, or that limit may return fewer items. There is also unresolved tension with readOnlyHint=false, which is surprising for a tool whose stated behavior is only 'Search' and 'Returns', yet the description never addresses or clarifies this.

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, front-loaded sentences with no filler, and the core action leads. The second sentence borders on restating what 'search' implies, so it is efficient but not maximally economical.

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 tool is simple (2 params, no nesting) and annotations plus a fully described schema cover most needs. But with no output schema, the description should say more about what a result looks like (IDs, ranking, truncation) than the vague 'top matching videos'.

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% – both 'query' and 'limit' (range and default) are fully documented in the schema. The description adds no syntax, filtering, or format guidance, so the schema does all the work; 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?

States a specific verb+resource ('Search YouTube videos by query') and confirms the return ('top matching videos'), which cleanly separates it from stats/comments/transcript siblings. However, it never distinguishes itself from the closest sibling youtube_videos (list vs. search), so differentiation is only partial.

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 when-to-use condition, no when-not-to-use, and no alternative is named. With siblings like youtube_videos, tiktok_search and youtube_channel_stats present, an agent gets no help deciding when keyword search is the right entry point.

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 discloses the returned payload (views, likes, comments, publish date, channel info), which is real value since there is no output schema. However, it never addresses the notable annotation profile: openWorldHint=true (external network call) and readOnlyHint=false are left unexplained, and there is no mention of quota/rate limits or behavior on private/deleted videos.

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?

One sentence, front-loaded with the action and resource, with the payload enumerated inline. No filler and nothing that fails to earn 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 one-parameter read tool this covers purpose and return shape adequately, and no output schema means the enumerated fields are the only return documentation. It would be fully complete with a note on external-call implications and failure modes (invalid or non-public URLs).

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 is a single parameter with 100% schema description coverage ("Public YouTube video URL"), so the schema already carries the meaning. The description adds nothing about accepted URL formats (shorts, youtu.be, with timestamps), leaving it at the baseline for a fully documented schema.

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 and resource ("Get engagement stats") and scopes it to "a single YouTube video," which separates it from channel-level siblings like youtube_channel_stats and youtube_videos. It stops short of naming an alternative tool explicitly, so it does not reach the sibling-routing clarity 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 phrase "single YouTube video" implies the usage boundary against the channel-level siblings, but there is no explicit when-to-use, when-not-to-use, or named alternative. The agent must infer routing from the scope word 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 are present but thin (readOnlyHint=false, idempotentHint=false, destructiveHint=false), so the bar is lowered. The description usefully discloses the return shape ('full text plus per-segment timings'), which is real value given there is no output schema. However, it omits failure behavior (no captions, private/age-restricted videos) and the readOnlyHint=false flag is odd for what is plainly a read operation, with nothing in the text resolving that ambiguity.

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, zero filler, with the action front-loaded and the return format following. Every clause 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 one-parameter read tool with no output schema, the description covers both what it fetches and what comes back, which is the essential information. It falls short only on edge-case behavior (missing captions, unsupported languages) that an agent would want before calling.

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 'url' parameter, so the schema already documents it as a 'Public YouTube video URL'. The description adds no additional parameter meaning (e.g., accepted URL forms, video IDs), so the 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 names a specific verb and resource ('Get the transcript (captions) of a YouTube video') and even disambiguates the term transcript with 'captions'. An agent can tell instantly that this is the YouTube-caption reader, distinct from the Instagram/TikTok siblings.

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 use this tool versus alternatives, nor any preconditions (public video, captions must exist, language selection). The description states what the tool does but never when it applies or fails.

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?

Goes well beyond the annotations by disclosing the credit cost model ('one credit per usable success'), sequential-within-a-deadline execution, partial-result retention, and the per-item fields to inspect (attempted, chargeStatus, errorCode). It also gives an explicit anti-retry policy, which the annotations do not cover.

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?

Four tight sentences, front-loaded with the core action and scope, with each subsequent sentence carrying distinct information (cost, execution model, result inspection, retry policy). Dense but no wasted phrasing.

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 helpfully names the response fields an agent must inspect (attempted, chargeStatus, errorCode) and covers credit cost and partial-result behavior. It leaves the exact meaning of 'deadline' and the transcript payload format unstated, a minor gap for an otherwise self-contained definition.

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 single 'urls' parameter is already fully documented in the schema, including the 1-5 range and credit cost. The description's restatement of the range and credit cost adds no syntax or format detail beyond the schema, so the 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?

States a specific verb and resource ('Retrieve transcripts') plus the batch scope ('1 to 5 pasted YouTube video URLs'), which cleanly separates it from the singular youtube_transcript sibling. An agent can tell what it does and how it differs from the single-URL tool without opening the schema.

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 '1 to 5 URLs' bound and the explicit 'Do not retry automatically' warning give some operational guidance, but the description never states when to prefer this bulk tool over youtube_transcript or what to do on partial failure beyond retaining results. Usage is implied rather than spelled out.

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 annotations, the description discloses two real behavioral traits: publication dates and descriptions may be missing, and full_details enrichment is capped at 30 videos. These are exactly the caveats an agent needs to set expectations. It does not address the odd readOnlyHint=false annotation or any auth/rate-limit behavior, keeping it short of a 5.

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 purpose and followed by the two caveats. The 30-video cap is duplicated verbatim from the schema description, which is minor waste but not bloat.

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 carries the burden of describing returns; it hints that dates and descriptions may be absent but never names the fields actually returned (video id, title, url) or how pagination/limit interplay works. Adequate for a simple list tool, but not complete.

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 url, limit, and full_details are already fully documented in the schema, including the 1-100 range and the 30-video cap. The description restates the full_details cap but adds no new parameter semantics, so the 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?

"List videos from a public YouTube channel or playlist" states a concrete verb and resource, which separates it from siblings like youtube_comments, youtube_channel_stats, and youtube_transcript. It stops short of explicitly contrasting with youtube_search or tiktok_channel_videos, leaving the channel-vs-search distinction to inference.

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 is implied by the phrase "from a public YouTube channel or playlist," which suggests the tool takes a channel/playlist URL rather than a query. There is no explicit when-to-use guidance, no statement of when to prefer youtube_search or tiktok_channel_videos, and no prerequisites such as requiring a public channel.

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