fenwick_tree

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

No annotations are provided, so the description carries the full behavioral burden. It implies a stateless compute (build then run operations) but says nothing about return format, whether results preserve order relative to operations, error handling for out-of-range indices, or complexity. The operation types are only surfaced via the schema, not the description.

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?

A single efficient sentence front-loads the core purpose with zero filler. It is appropriately sized, though the terseness comes at the cost of the routing and output detail noted elsewhere.

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?

With no annotations and no output schema, the description must cover behavior and results, and it only partially does. It covers the build-and-operate model but never states what a query or update returns, which matters most for a computation tool whose output shape is otherwise undefined.

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 both parameters and the three operation shapes are already documented structurally. The description adds conceptual framing (values -> tree -> update/query) but no extra syntax or semantics beyond the schema. Baseline 3 is appropriate.

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 gives a specific verb+resource: builds a Fenwick tree (Binary Indexed Tree) from an input array and runs point updates plus range sum queries. That is unambiguous about what the tool computes. It fails to differentiate from close siblings like fenwick_range and fenwick_2d, which an agent would need to distinguish before choosing.

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?

There is no when-to-use or when-not-to-use guidance at all. Given that fenwick_range and fenwick_2d exist alongside this tool, the absence of any routing advice leaves the agent to guess which variant applies.

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