compare_charts

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

No annotations are provided, so the description must carry the full burden. It details inputs but omits behavioral traits such as rate limits, data frequency, or what happens with large ISIN lists. The existence of an output schema partially compensates, but more transparency is needed.

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 front-loaded with a clear one-liner followed by a bulleted parameter list. Every sentence serves a purpose, with no redundancy or wasted words.

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 the output schema exists, return value explanation is not needed. The description covers most inputs but omits pagination parameters and error handling. For a 9-parameter tool, it is reasonably complete.

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?

With 0% schema description coverage, the description adds significant meaning to all listed parameters (e.g., enumerations for currency, dates, input_value, output_value). However, it fails to mention limit and offset (pagination), which are present in the schema.

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?

Description clearly states 'Compare historical chart series for multiple ETFs,' specifying a distinct verb and resource, and distinguishes from sibling tools like get_chart (single ETF) and search_etfs (search only).

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 covers parameter meanings but lacks explicit guidance on when to use compare_charts versus alternatives or exclusions. However, the context from sibling tools implies it is for multi-ETF comparison, making usage relatively clear.

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