get_fundamentals_definitions

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

With no annotations provided, the description carries the full burden of behavioral disclosure. The verb 'fetches' implies a read-only operation, but the description does not add context about response format, whether the values are static, or any potential limits. For a zero-parameter reference tool, this is adequate but minimal.

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, concise sentence that immediately conveys the tool's purpose. There is no unnecessary detail or repetition, earning a perfect score for efficiency.

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, zero-parameter tool with no output schema, the description adequately covers the core functionality: it returns available fundamental metrics and their definitions. It could be slightly more explicit about the return format (e.g., 'a list of metric names with definitions'), but the current wording is clear enough for an agent to understand the tool's role.

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 has no parameters, so the description does not need to explain parameter meanings. The schema shows an empty properties object, and the description sufficiently indicates that the tool returns available metrics and definitions. Per the rubric, zero parameters warrant a baseline score of 4.

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's function: 'Fetches available fundamental metrics and their definitions.' It uses a specific verb ('Fetches') and identifies the resource ('available fundamental metrics and their definitions'), making it easy to distinguish from sibling tools like get_fundamentals_statements or get_fundamentals_daily_metrics, which focus on data retrieval rather than definitions.

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 provides no guidance on when to use this tool versus alternatives. It does not mention that it is a reference lookup for understanding metric definitions, nor does it contrast with siblings such as get_fundamentals_meta or get_fundamentals_statements. The agent is left to infer usage from the name alone.

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