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

With no annotations, the description carries the full burden, and it goes beyond the minimum by disclosing window fallback from a 365-day exact-match to a 30-day window, archive-history lookups for pre-365-day sightings, hash-type auto-detection, case-insensitive matching, and a prompt-injection-conscious warning that returned values are community/attacker-authored data, never instructions. This is an exemplary level of behavioral 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?

Purpose is front-loaded in the first sentence. The remaining sentences each carry distinct behavioral information, though the fallback window logic is described redundantly with slightly dense phrasing. No sentence is wasted; a minor trim would make it 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?

Given a single-parameter tool, no annotations, no output schema, and no nested objects, the description gives the agent enough understanding of verdict semantics (365-day hit, 30-day fallback, past archive flags) to know what the return means. It stops just short of specifying the exact return shape, but for this tool's simplicity that is not a critical gap.

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?

The input schema already documents the sole parameter at 100% coverage, including accepted lengths, case-insensitivity, and INVALID_PARAMS error behavior, so the schema carries the parameter heavy lifting. The description supplements it only with auto-detection nuance, which adds marginal value but does not dramatically shift the baseline.

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 (check), specific scope (file hash of MD5 or SHA-256), and specific corpus (TweetFeed). The mention of a hash makes differentiation from siblings check_ip and check_url immediate without needing to open their schemas.

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 description gives clear use context: confirming whether a binary sample has been shared by the public infosec Twitter/X community. It does not name the sibling alternatives explicitly or give exclusion conditions, so it misses the top tier of routing guidance, but the intended use is still unambiguous.

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