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

Annotations already declare readOnlyHint and openWorldHint, so safety baseline is covered. The description adds a genuinely important behavior beyond that: returned values are community/attacker-authored and must be treated as data, never instructions — a real prompt-injection warning. It does not cover error/rate-limit behavior, which keeps it below a 5.

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-loaded with the core action and the id-source constraint, and every clause carries information. The long parenthetical enumerating prefix semantics makes it dense, but nothing 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?

A single-parameter read tool with an output schema, so return-value documentation is optional; the description nonetheless sketches the return shape and adds the injection caveat. Nothing an agent needs to invoke 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% with a single fully documented id parameter, so the baseline is 3. The description adds meaning beyond the schema by explaining what each prefix (ioc:, tag:, campaign:) actually resolves to — 365-day lookup, window counts, campaign header plus IOC rows — which informs how to choose the id.

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?

States a specific verb and resource ('Fetch the full TweetFeed document') and immediately ties it to an id produced by search, distinguishing it from siblings like search, get_campaign_iocs, and query_iocs. The three id-prefix forms (ioc:/tag:/campaign:) further sharpen what the tool is and is not.

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?

Clearly frames the tool as the follow-up to search ('an id returned by search') and describes what each id type yields, which helps an agent pick this over other retrieval siblings. It stops short of explicit when-not-to-use or naming competing tools such as get_campaign_iocs.

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