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

Annotations cover the safety profile (readOnly, idempotent, non-open-world), and the description adds genuinely useful context: results are ordered newest first, the visitor figure is a 48-hour estimate, and tracked-link campaigns yield exact numbers instead. Rate limits and pagination behavior are not mentioned, but the estimate-versus-exact caveat is a meaningful disclosure 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?

Two sentences, with the resource and source platforms front-loaded and the estimate caveat placed last where it matters. Nothing is padded, though the platforms parenthetical slightly muddies the opening sentence.

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-shape burden and does name the key fields (score, comments, visitor estimate) plus ordering. It lacks any note on pagination or result limits beyond the schema's default, but is largely sufficient for a simple read-only listing 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 coverage is 75%, with limit, range, and domain already documented in the schema, so the baseline is 3. The description adds the data window for the visitor figure but omits half the platform enum (x, linkedin, bluesky, youtube, web) while naming only hn, lobsters, and reddit, which could mislead an agent about valid values.

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 ('public posts and comments ... that link this site') and enumerates what comes back (score, comments, visitor estimate), which clearly separates it from sibling aggregations like top_sources or query_visits. An agent can identify the 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?

Usage is only implied: it shows inbound-link mentions over a lookback window, but never states when to prefer this over top_sources, query_visits, or get_campaign_results. No exclusions or prerequisites are given, 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.