discussion_search

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

With no annotations, the description carries the full burden and does so: it discloses partial-failure semantics ('A source that is down reports an error without failing the call'), the exact return shape (title, snippet, linked URL, discussion URL, author, points, comment count, date, up to 5 top comments, plus an aggregate summary), the per-call cost ($0.006 USDC) and p99 latency (6000ms). These are the operationally relevant facts an agent needs and none are derivable from 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 purpose, scope exclusions, return shape, parameters, cost and latency are all packed into one dense paragraph with the most important information front-loaded and zero filler sentences. It reads as a wall of text rather than being broken into scannable clauses, which costs it a point but nothing in it is wasted.

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 7-parameter federated-search tool with no annotations and no output schema, the description covers everything an agent needs: what it searches, how to call it, the one-of requirement on query/url, per-source limits, failure behavior, and the fields returned including the aggregate summary. Nothing material is left to inference.

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 only 43% and the schema lists zero required parameters, yet the description supplies the missing semantics: it states that query or url is required (one of the two) — a constraint the schema does not express — and enumerates defaults and ranges for sources, sort, days (1–3650), limit (1–20, default 5) and comments (0–5, default 2). This is a genuine compensation for the coverage gap rather than a restatement.

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 opens with a specific verb+resource ('Find out what people say about a topic or a specific link') and immediately names the three sources it federates (HN, Bluesky, Lemmy) plus the two search modes (keywords or URL). It distinguishes itself from the many other search siblings (news_search, web_search, dev_search, search_read) by scoping to social-discussion sources and by explicitly excluding Reddit and X.

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 gives concrete use cases ('product launches, articles and competitors') and states the URL mode 'finds every thread that shared that link', which tells the agent when URL input beats keyword input. It also rules out Reddit and X, which prevents mis-selection. It stops short of naming an alternative sibling to use instead, so it is clear context without explicit routing.

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