market_snapshot

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

Annotations already declare read-only, idempotent, open-world, non-destructive behavior. The description adds material beyond annotations: free public data, no API key, nothing signed or spent, and failure behavior on unknown symbols or unreachable upstream sources.

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 front-loaded and organized into purpose, use cases, exclusions, returns, and example. It is somewhat verbose, repeating 'one call' and including an example response that largely restates the return fields, but no section is misleading or wasted.

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 no input schema and no output schema, the description carries the full documentation burden. It lists returned fields and provides an example response, plus safety and failure context, so an agent has enough information to invoke and interpret the tool.

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 takes zero input parameters, so there are no parameter semantics to document. Per the baseline for zero-parameter tools, a 4 is appropriate; the description correctly does not invent parameter guidance.

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 combined resource: macro and crypto market snapshot in one call. It clearly distinguishes itself from siblings such as token_price, gas_tracker, and funding_rates. However, it advertises 'Fed rate, inflation proxy' while the listed returns do not include those fields, creating a minor mismatch.

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 'Use when' and 'Not for' sections explicitly define the intended context and name alternatives for single-asset depth and historical/time-series queries. An agent can route between this tool and token_price, gas_tracker, funding_rates, or dune_query without inference.

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