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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds real behavioral context beyond that: results are historical dataset records rather than live store pages, which materially affects how the agent should treat the output. It doesn't mention pagination or rate limits, so it stops short of 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?

Two sentences, zero waste. The purpose is front-loaded and the important historical-vs-live caveat plus the alternative endpoint follow immediately, in priority order.

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?

The presence of an output schema means return values need not be explained, and the description covers purpose and the historical nature well. However, for a 16-parameter tool with no schema descriptions, the complete absence of parameter guidance leaves a real completeness 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?

There are 16 parameters with 0% schema description coverage, so the description must compensate for the naming burden. It only offers the vague phrase 'by query and filters,' adding no meaning for q, page, sort, status, category, developer, item_type, min_users, or the rest. This leaves almost all parameter semantics undocumented.

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 and resource ('Search stored Chrome Web Store extension, theme, and legacy app snapshots') plus scope ('by query and filters'), and it explicitly names the sibling item endpoint, so an agent can route between search and detail without opening either schema.

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 gives clear usage context ('use the related item endpoint for one snapshot's details') and warns that results are historical records, not live store pages. It lacks explicit when-not conditions, but the alternative endpoint and the historical caveat cover the main selection decision.

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