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

Annotations already establish readOnly/idempotent/non-destructive, and the description adds substantial context beyond them: cost (free), return contents (cited evidence, review dates, limitations, snapshot_sha256), and deliberate preview truncation (scope, interface summaries, representative findings; no exact operational schemas or licensed ZIP). The preview_payload_sha256 distinction and the 'no live testing' caveat are exactly the behavioral details annotations cannot express.

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?

The most decision-critical facts (what it previews, where route_id comes from, that it's free) are front-loaded, and there is little waste. It is a dense single block, though, and the preview-scope and version caveats could be separated for faster scanning.

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?

No output schema exists, so the description must describe returns, and it does (cited evidence, review dates, limitations, snapshot_sha256, differing hashes per product type). Combined with annotations covering the safety profile, an agent has everything needed to call this correctly and interpret what comes back.

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 description coverage is 0%, so the description carries the burden, and it does explain both parameters: route_id's provenance and version's restriction to exact advisory-listed versions rather than ranges. It stops short of stating format or the fact that version is optional-and-exact-only in a fully explicit way, leaving a small gap.

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 ('Preview a published answer or pack') and immediately identifies the source of the required identifier ('route_id from find_evidence_questions or find_package_advisories'). This distinguishes it cleanly from all three siblings, which are finders or a pricing tool.

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 routes the agent: 'For prices and licences, call get_index_access_options', and defines the version filter's scope ('exact advisory-listed versions only, not ranges or safety'). It also declares the boundaries ('Free', 'No paid saving or live testing'), so when-to-use and when-not-to-use are both covered.

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