get_market_features

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

With no annotations, the description carries the full transparency burden. It discloses success and error return shapes ({ticker, as_of, features} or {error: reason}) and specifies failure conditions ('unsupported ticker' or fetch failure). It does not mention side effects or permissions, but as a read-only 'fetch and compute' operation, this is acceptably complete.

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 tightly structured in five sentences. It front-loads the core action, then adds example, return format, error case, and workflow order. Every sentence contributes useful detail without redundancy or fluff.

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 simple one-parameter tool with an output schema, the description covers all essential context: what it does, argument format via examples, return structure, error behavior, and its role in the two-step process with get_forex_signal. It leaves feature names to the output schema, which is appropriate.

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 0%, so the description must compensate for the bare parameter definition. It provides two concrete ticker examples ('EURUSD=X', 'GBPUSD=X') and implies a Yahoo Finance format, but does not fully define the valid pattern or enumerate supported pairs. This is partial compensation, leaving some ambiguity about acceptable inputs.

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 'Fetch and compute the feature vector for a forex pair,' which is a specific verb+resource combination. It clearly distinguishes from sibling tool get_forex_signal by stating 'Call this first, inspect the features, then pass them to get_forex_signal,' establishing a unique role in the workflow.

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?

Explicit guidance: 'Call this first, inspect the features, then pass them to get_forex_signal.' This provides an explicit sequence relative to the sibling and tells the agent exactly when to use this tool. It lacks explicit 'when-not' scenarios, but the workflow instruction is strong enough to warrant full credit.

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