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

Annotations already establish readOnly/non-destructive/open-world, so the safety profile is covered. The description adds a genuinely useful trait those annotations do not carry: the data is cached, which tells the agent results may be stale. It does not quantify cache TTL, but this is real added behavioral context.

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 tightly packed sentences. The core payload is front-loaded and the operational caveat ('cached') lands before the closing note, with no filler or repetition.

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?

With an output schema present, the description need not explain return shapes, and it does not need to — the field list is somewhat redundant with the schema. For a no-param cached read tool this is essentially complete; only cache staleness duration is left unspecified.

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?

Zero parameters, so the baseline is 4. The description reinforces this with 'no input required', correctly telling the agent there is nothing to supply and no filtering options to consider.

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 names the resource precisely (crypto market sentiment snapshot) and enumerates its payload — BTC price, 24h change, fear/greed, confidence, source-attributed reasoning. That content list implicitly separates it from siblings like get_market_regime or get_market_history, though no sibling is named explicitly.

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?

'Current' and 'snapshot' imply this is the real-time-state lookup rather than the historical one (get_market_history) or the regime classifier (get_market_regime), so usage is inferable. There is no explicit when-to-use vs. alternative statement, and no guidance on how the cached freshness limit should affect the decision to call it.

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