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

Annotations already declare openWorldHint=true, idempotentHint=false and destructiveHint=false, so the description's best value is the async contract: it returns an investigationId immediately rather than results. It also discloses the tier restriction and the deliberate restriction on people-centric OSINT. It doesn't mention cost, rate limits or how long an investigation persists, 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?

Three sentences, each with a distinct job: what it does, the access restriction, and the async return plus follow-up tools. Front-loaded with the action and no wasted text.

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 an async-job starter with no output schema, the description supplies everything an agent needs: the immediate investigationId return, the two tools that complete the workflow, and the tier gate that may block the call. Nothing material 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?

With a single required parameter at 100% schema description coverage, the schema already documents 'query'. The description only narrows that generic schema text by implying the query is a username, adding modest value over the structured field.

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 ('Start an async OSINT investigation') and resource ('a username'), plus the scope of the investigation (cross-platform presence, breach correlation). This clearly separates it from osint_investigate_email_start and osint_investigate_domain_start, whose subject types are different.

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?

Explicitly says to poll with osint_investigation_status and retrieve results with osint_investigation_report, so the follow-up path is unambiguous. It also states the owner/enterprise tier restriction and the misuse guardrail. It stops short of explicitly comparing against the email/domain/infrastructure start siblings, relying on the subject-type naming instead.

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