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

Beyond the readOnlyHint and openWorldHint annotations, the description adds valuable context: it is heuristic, has low/medium confidence, explicitly says 'NOT financial advice', and discloses that war/hard-politics events are excluded. This explains the tool's limitations and nature.

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 a single dense paragraph that front-loads the core purpose ('News → markets recommender') and packs in classification, mapping, confidence, and exclusions without redundancy. Slightly long but every sentence adds useful information.

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 read-only tool with no output schema, the description covers the key aspects: inputs, processing logic, output shape (event → affected markets → lean), confidence levels, and exclusions. It doesn't detail response format or error behavior, but that's acceptable given the tool's simplicity and the rich schema.

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 coverage is 100%, so the baseline is 3. The description lists the filter parameters (hours, event_type, min_confidence, limit) and contextualizes them within the tool's flow, but doesn't add detail beyond the schema's own descriptions.

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 is a 'News → markets recommender' that pulls headlines, classifies event types, extracts assets, maps to HIP-4 markets, and assigns directional leans. This specific verb+resource distinguishes it from siblings like get_recent_news or get_news_correlation.

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 implies when to use it (for news-driven market signal generation) and states 'war/hard-politics excluded' as a scope limitation. It doesn't explicitly name alternative tools, but the use case is clear enough that an agent could infer when to choose it over related news and signal tools.

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