crypto_news

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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuinely new context: free, no API key, nothing signed or spent, and the failure modes (unknown symbol, unreachable upstream). Rate limits or pagination behavior are not mentioned, keeping it short of a 5.

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?

Front-loaded one-line summary followed by clearly labelled Use when / Not for / Returns / Example blocks. The embedded example response is long but earns its place since no output schema exists; minor verbosity otherwise.

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 output schema, the description carries the return contract itself (headlines[] with title, url, sentiment, score, published_at) and even a concrete example payload. Combined with the source, cost and failure behavior, an agent has everything needed to call it correctly.

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 100%, so both parameters (filter enum, currencies) are already documented in the schema. The description only echoes 'for any token' and shows a currencies example; it adds no format or default semantics beyond the schema. Baseline 3 applies.

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?

States a specific verb+resource ('Latest crypto news and community sentiment from r/CryptoCurrency') plus scope ('for any token'). The source and content type are explicit, distinguishing it from generic search tools at a glance.

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?

Provides an explicit 'Use when' trigger and a 'Not for' clause that names three alternatives (web_search, url_reader, fear_greed_index) with the condition that selects each. Nothing is left to inference.

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