get_indices_performance

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

No annotations are provided, so the description carries full burden. It mentions fetching data from an API and its usefulness but fails to disclose critical behavioral traits such as rate limits, authentication requirements, error handling, pagination behavior (implied by 'page' parameter but not explained), or data freshness. This leaves significant gaps for an agent to understand operational constraints.

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 appropriately sized with two sentences: the first states the purpose and data included, and the second provides usage context. It is front-loaded with the core functionality, though the second sentence could be more specific to earn a perfect score.

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?

Given no annotations and no output schema, the description is moderately complete for a read-only tool with full schema coverage. It covers the what and why but lacks details on behavioral aspects like API limits or response format, which are important for an agent to use it effectively without structured output guidance.

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 the schema already documents all 5 parameters thoroughly with examples and constraints. The description adds no additional parameter semantics beyond implying date-range filtering and ROI data, which is partially covered by the schema. Baseline 3 is appropriate as the schema does the heavy lifting.

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 action ('fetch historical performance data') and resource ('for a given index'), specifying it includes cumulative ROI over time from Token Metrics API. It distinguishes from siblings by focusing on index performance rather than holdings, metrics, or token data, though it doesn't explicitly contrast with similar tools like get_indices.

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 usage for analyzing index trends and evaluating investment performance, providing general context. However, it lacks explicit guidance on when to use this tool versus alternatives like get_indices (which might list indices) or get_tokens_quant_metrics (which might provide similar data for tokens), with no mention of exclusions or prerequisites.

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