get_nav_history

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

Without annotations the description carries the full burden, and it delivers a genuinely non-obvious behavior: responses are silently truncated to the most recent `max_points` within the range, which prevents an agent from assuming full-range data. It also discloses accepted date formats. Gaps remain on what happens when start/end are omitted (schema default null is unexplained) and whether NAV is adjusted.

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?

Two short sentences, zero filler, with the resource scope front-loaded and the truncation caveat immediately after. Every sentence earns its place.

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?

An output schema exists so return values need no explanation, but with no annotations and 0% schema coverage the description should also state default-range behavior when dates are null and how to obtain a scheme_code. Adequate for a simple read, but leaves real decisions to inference.

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 0%, so the description must compensate — and it does for most params: it names the two accepted date formats for start_date/end_date and clarifies that max_points caps the most recent points, not arbitrary ones. It does not explain the semantics of null dates or where scheme_code comes from.

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?

States the resource precisely ('NAV history for a scheme') and implicitly the operation (retrieve). An agent can distinguish it from get_scheme_quote (current price) and get_scheme_details by the 'history' term, though it never explicitly contrasts with siblings like get_stock_history.

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?

No guidance on when to use this versus get_scheme_quote, get_scheme_details, or get_rolling_returns, and no exclusions or prerequisites. The only implied usage comes from the tool name itself.

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