News providers

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

Annotations already mark readOnlyHint and openWorldHint; the description adds valuable behavior beyond them: only subscribed providers are returned, free API feeds require separate IBKR market-data subscriptions, and not_found is returned when the login has none. This explains filtering and failure behavior beyond what annotations convey.

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 main verb and resource appear in the first sentence, followed by compact usage, subscription caveat, and error information. There is no filler or redundant restatement of the title or schema.

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?

For a zero-parameter, read-only list tool with an output schema, the description covers purpose, downstream consumers, subscription caveat, and error behavior. An agent has everything needed to call it correctly and interpret the result.

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 input schema has no parameters and schema coverage is 100%, so there are no parameter semantics to document; the 0-parameter baseline applies. The description's mention of returning 'code and name' is output-focused and does not need to compensate for any parameter gaps.

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 opens with a specific verb and resource: 'List the news providers this IBKR login can use through the API (code and name).' This unambiguously states what the tool returns and its scope, and it is clearly distinct from sibling news tools like get_news_article and subscribe_news.

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?

It provides clear downstream usage guidance: 'Use the codes with get_historical_news, get_news_article and subscribe_news,' and it explains the subscription limitation ('Only subscribed providers are listed'). It does not explicitly enumerate when not to use the tool, but the context and workflow are clear enough.

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