Market overview

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds 'Read-only; not a recommendation', which reinforces the read-only nature and adds a disclaimer about non-advice, but it does not disclose additional behavioral traits such as how the period parameter affects the data or whether any state changes occur (which are already covered by annotations). The added value beyond annotations is modest.

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 two sentences and front-loads the core content (asset list and period changes) before the disclaimer. It is concise with no fluff. The only minor improvement would be to separate the disclaimer more clearly, but overall it is efficient and well-structured.

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 description lists the covered assets and metrics, giving an idea of what the snapshot includes. However, it does not explain how the period parameter affects the output (e.g., whether it shows performance over that period or just current values), nor does it specify the format of the snapshot. Since the tool has an output schema (as indicated by context signals), the return format may be inferred, but the description still lacks clarity on the period's role. This leaves a notable gap for an agent to correctly interpret the tool's behavior.

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%, meaning the description carries the full burden of explaining the 'period' parameter. The description only says 'with period changes' without specifying what the period does, how it influences the snapshot, or mapping to the enum values (1mo, 3mo, etc.). The enum values are self-explanatory to a degree, but the description fails to clarify that the period likely selects the time range for the snapshot, leaving ambiguity.

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 clearly states the tool provides a snapshot of a specific list of assets and metrics (BTC, ETH, SOL, gold, SPY, QQQ, EUR/USD, US 2y/10y yields, CPI) and mentions period changes. This distinguishes it from sibling tools like search_markets or research_asset, which are more specific. The verb 'Snapshot' and resource list make the purpose unambiguous.

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 its siblings (search_markets, research_asset, etc.). It does not mention conditions, alternatives, or exclusions. An agent cannot tell whether this should be used for a broad market overview versus a targeted search or deep research from the description alone.

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