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

No annotations are provided, so the description carries the full burden. It discloses the categories of data returned, which is adequate for a read-only, zero-parameter snapshot tool, but it does not mention data freshness, latency, or other behavioral characteristics. It is not misleading.

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 description is a single, information-dense sentence with a clear structure: a label and a comma-separated list of content categories. Every word earns its place, with no redundancy.

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?

Given the tool has no parameters, an output schema exists, and the purpose is a straightforward read-only market overview, the description fully covers the surface area. Usage guidance would be nice but is not essential for completeness in this simple case.

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?

The tool has zero parameters and schema coverage is 100%. The description adds no parameter-level detail, but none is needed; the baseline of 4 applies because no parameter ambiguity exists.

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 'Market-wide snapshot: indices, top_gainers, top_losers, most_active, breadth' clearly identifies a market-wide aggregate resource and enumerates its components, distinguishing it from sibling stock-specific tools. It lacks an explicit verb in the description itself, but the name provides 'get' and the scope is specific.

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?

The description provides no guidance on when to use this tool versus alternatives, no exclusions, and no recommendations. Context from sibling names implies it is for market-level data, but the description itself does not state this.

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