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

Beyond readOnlyHint/openWorldHint, it discloses the 30-day window, the case-insensitive substring behavior, the returned fields (date, researcher handle, value, tags, source tweet URL), and adds a security warning that returned values are community/attacker-authored and must be treated as data. This goes well beyond what annotations already provide.

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 sentences, each earning its place: function, use case/matching rule, return fields plus warning. The core action is front-loaded in the first sentence, and there is no fluff or repetition of schema content.

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 compensates by listing the returned fields and explaining the data-safety caveat. Parameter semantics, matching behavior, and time window are all covered. Nothing an agent needs to call it correctly 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 coverage is 100% and the schema already describes the url parameter (URL or substring, case-insensitive) with an example. The description adds that the match is against the 'value' field of type=url IOCs, which is a small addition, but the schema carries the semantic weight. Baseline 3 is appropriate.

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 states a specific verb ('Check') and resource ('TweetFeed corpus') with a precise scope: past 30 days, case-insensitive substring match against the 'value' field of type=url IOCs. This clearly distinguishes it from sibling tools check_hash and check_ip, which operate on different IOC types.

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 explicitly frames when the tool is useful: 'confirming if an observed URL has been flagged by the public infosec Twitter/X community.' It does not explicitly name alternative tools, but the sibling set (check_hash, check_ip, query_iocs) makes the use case clear. Lacks an explicit 'use this instead of X' exclusion, hence 4.

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