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

Annotations already declare readOnly/idempotent/closed-world, so the safety profile is covered. The description adds real behavioral context beyond them: data provenance (summed from the Gateway transaction stream) and a meaningful coverage limitation ('counts cover user transactions only'), which an agent must know to interpret the numbers correctly.

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?

Front-loaded with the resource and scope, then the measures, then the narrowing guidance. Dense and largely waste-free, though the trailing sentence about /charts and the CSV download is more contextual pointer than invocation-critical and slightly dilutes the focus.

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 output schema, the description carries the burden of describing the returned data and does so fully: granularity, coverage window, provenance, and the enumerated columns. Nothing an agent needs to call or interpret this tool is missing.

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%, with both `from` and `to` documented in the schema including format (YYYY-MM-DD) and default behavior. The description only restates the filtering action ('Narrow with from/to') and adds no syntax or semantics beyond the schema, so the baseline 3 applies.

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 a specific verb+resource (daily Radix mainnet activity) and then enumerates the exact measures returned (transactions, active/new accounts, components, resources, NFTs, fees, XRD burned, royalties). It also pins the scope precisely: one row per UTC day since Babylon (28 September 2023). An agent knows exactly what this returns without opening the schema.

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?

Gives clear operative guidance ('Narrow with from/to') and points to sibling artifacts (/charts, /api/charts/activity?format=csv) for the same data. It does not state any when-not condition or name a competing tool, but the surrounding siblings (wiki page tools) make the domain unambiguous.

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