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

Annotations already establish this is a non-destructive local read (readOnlyHint=true, openWorldHint=false), so the safety profile is covered. The description adds genuinely new behavioral information: the response is not just the comment but its ancestor chain 'up to the top' and its direct replies, which tells the agent what context comes back. It omits any note on failure modes when a comment number doesn't exist, 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?

A single sentence with zero filler, front-loaded with the operation and immediately qualified by the returned scope. 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?

With only two required, fully described parameters and no output schema, the description's job is to convey what the call yields — which it does via the ancestor/replies scope. It is nearly complete, lacking only a hint about behavior when the comment id is invalid.

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 (thread, comment) are already fully documented, including the accepted comment-number forms in the schema itself. The description's '[cN]' notation restates what the schema already says and adds no new meaning. 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?

States a specific verb and resource — 'Returns one comment by its [cN] number' — and goes on to define the exact scope of what comes back (ancestor chain plus direct replies). That scope detail implicitly separates it from search_comments and read_thread, though neither sibling is named outright.

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 when-to-use guidance and no mention of alternatives. The phrase 'by its [cN] number' faintly implies you already need the identifier (so search_comments would come first), but that routing 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 already cover the safety profile (readOnlyHint=true, openWorldHint=false), yet the description still adds behavior: results are ordered newest first and include comment counts, and it reveals that the primary output is a thread id used by other tools. This is useful context beyond structured fields, though nothing is said about pagination or result limits.

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, zero filler. The resource and ordering lead, and the actionable workflow instruction follows. 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 zero-required-param listing tool with annotations covering safety and no output schema, the description supplies what an agent needs: what is listed, the ordering, the presence of comment counts, and the next step. Nothing essential is missing.

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

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

Schema description coverage is 100% for the single optional `query` parameter, so the schema already documents that it filters by title substring. The description adds nothing to parameter meaning, which is the expected baseline when the schema does the work.

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 (Lists) and resource (Reddit and Hacker News threads exported via Comment Scraper), and adds scope details: newest first, with comment counts. It also implicitly distinguishes itself from read_thread by stating it returns thread ids to be used with that sibling.

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?

"Call this first to get a thread id" gives explicit sequencing guidance relative to read_thread, so an agent knows when this tool is the entry point. It stops short of naming exclusions or comparing against search_comments/get_comment, but the workflow positioning is clear.

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 safety (readOnlyHint=true, openWorldHint=false), and the description adds behavior they cannot: the exact rendered return format including score and relative age, the pagination continuation rule, and the citation convention. It does not cover failure modes (unknown thread id, fuzzy title resolution) or rate limits, so it is strong but not complete.

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 tight sentences, front-loaded with what is returned, then the paging rule, then the citation requirement. No filler and no restatement of the tool name or title.

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 carries the full burden of describing the return value, and it does so concretely with a format sample plus the paging loop. Only error handling and the relationship to sibling tools are 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 coverage is 100%, so the baseline is 3. The description goes beyond it by explaining the offset parameter as a continuation token ('call again with the offset given at the end'), which tells the agent how limit/offset interact across calls; min_score and the title-matching behavior of 'thread' remain schema-only.

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 — returns a thread's post plus its comments — and specifies the exact output shape (numbered Markdown with [cN] references). It is clearly distinct from get_comment and search_comments in effect, though it never names those siblings to make the boundary explicit.

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 real operational guidance for pagination ('call again with the offset given at the end') and for citing comments, which tells the agent how to use the result. It stops short of saying when to choose read_thread over search_comments or get_comment, so the alternative-selection half of the guidance is absent.

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

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds useful behavioral detail by disclosing the shape of each match (thread, [cN] number, score), which reveals results are ranked, but says nothing about pagination behavior, result ordering rules, or cost/limits.

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 with the search scope front-loaded and the return shape second; every clause carries information and there is 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 three-parameter read-only search with no output schema, the description covers scope, matching semantics, and return contents, which is close to sufficient. Only minor gaps remain, such as ordering of scored matches and whether limit truncates silently.

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 limit, query and thread are all documented in the schema, which sets the baseline at 3. The description restates the AND-matching semantics of query and the single-thread option without adding format, syntax, or ranking-weight details 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?

States a specific verb+resource (finds comments) plus the scope of the search (all exported threads, or one) and the return payload (thread, [cN] number, score). It is distinguishable from get_comment by its cross-thread search scope, but it never names a sibling or explicitly contrasts with them.

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 'across every exported thread (or one thread)' and the thread parameter hint at when to narrow the search, implying usage rather than stating it. There is no explicit when-to-use/when-not guidance and no alternative tool is named, so the agent must infer the routing.

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