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

Annotations only declare readOnlyHint and openWorldHint; the description goes well beyond them by disclosing the 365-day exact-match window, the 30-day substring fallback with a concrete example ('1.2.3' matches '1.2.3.4'), and that pre-365-day archive history can still surface a past sighting. It also warns that returned field values are attacker-authored and must be treated as data, not instructions — a genuine safety disclosure.

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 question, then matching mechanics, use case, input tip, and the injection warning — a logical order where every sentence carries information. The nested parenthetical about the fallback window is dense, but nothing is 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 single-parameter read-only lookup with annotations covering the safety profile, the description covers matching behavior, fallback, archive history, and data-trust caveats. There is no output schema, so the exact verdict structure is only implied by phrases like 'clean verdict' and 'flags older archive history' — a minor gap, not a blocking one.

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 'ip' parameter, so baseline is 3. The description adds real value on top: 'Pass a full IPv4 / IPv6 string for the best exact-match hit rate,' which explains why the input format affects result quality — information the schema's example alone does not convey.

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?

Opens with a specific verb and resource: 'Check whether an IP address appears in the TweetFeed corpus,' and immediately scopes the corpus and matching semantics. Within the check_hash / check_url family the IP scoping makes the tool's identity unambiguous 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?

Gives a concrete use case — 'confirming if an observed IP has been flagged as attacker infrastructure (C2, scanner, phishing host)' — which tells the agent when this tool is the right call. It stops short of naming alternatives or stating when not to use it (e.g. versus enrich_ioc or query_iocs).

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