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

With no annotations, the description carries the full behavioral burden, yet it only reveals that statistics are computed over 'persisted' observations. It omits whether the data is cached, what aggregation or windowing is applied, and any read-only/permission context an agent would need before calling it.

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?

It is a single front-loaded sentence with no padding, which is structurally clean. But it is terse to the point of under-specification for a tool with two undocumented parameters, so conciseness here shades into incompleteness.

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?

An output schema exists, so return formatting needn't be described. Still, for a computed index tool with no annotations and 0% parameter coverage, the description omits which statistics are returned, the meaning of the observation window, and how it relates to sibling price/availability tools.

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% and there are two parameters, so the description must compensate. It never explains the required 'gpu' identifier (string, id vs. model name?) nor the 'days' window (default 7) or what it limits, leaving both parameters semantically 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 gives a verb ('Return') and a resource ('descriptive statistics over persisted GPU observations'), so the general action is clear. However, it never mentions pricing or an 'index' despite the tool name get_price_index, and it doesn't state which statistics are produced, so it barely distinguishes itself from siblings like gpufeed_get_history or gpufeed_get_cheapest.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives such as gpufeed_get_history or gpufeed_get_cheapest. An agent gets no signal about when this index is preferable to the other gpufeed retrieval tools.

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