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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered by structured data. The description does add real behavioral context beyond that — points are evenly spaced, historical only (past heights), and each point is dated — but it omits sampling density, which chains are supported, and any rate/limit behavior.

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 functional sentence is dense and front-loaded, but it terminates mid-clause, and the trailing line about 'a sponsor seat on The Network' is server/identity boilerplate that earns no place in a routing description. Effective content is short; there is both waste and incompleteness.

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?

There is no output schema, so the description must carry the burden of telling the agent what comes back — it only gestures at 'each point dated by its block' without stating the series shape, resolution, or chain scope. Combined with the undocumented address input and the truncated text, an agent cannot fully predict how to call it or what it receives.

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?

The schema exposes zero declared properties (additionalProperties=true), so the description is the only clue to inputs — and it only hints 'one address' without saying how the address, chain, or number of points is supplied. With 0 parameters the basline is 4, but because the tool plainly requires an undocumented address/range input that neither schema nor description defines, that baseline is not earned.

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 names a specific verb+resource+scope: 'native balance of one address at evenly spaced past block heights, each point dated by its block.' That clearly distinguishes it from the sibling singularityagent__balance (a single point-in-time balance) and from history/portfolio tools. The sentence is truncated mid-example, so the full statement of purpose is never completed, which keeps it from a 5.

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?

It offers an implied use case ('for questions like "how has this wallet's ETH moved over time"'), which signals when an agent should reach for a series rather than a single balance. However, it names no alternatives explicitly, states no when-not conditions, and the example sentence is cut off before any second clause that might have covered comparison cases.

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