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

Beyond the readOnly/openWorld/idempotent annotations, the description discloses significant behavioral caveats: 'added is exact', 'changed only reflects recorded events', 'removed is approximate', and the result should be treated as change notification, not a complete replication log. It also advises re-pulling the full export periodically. This adds real value beyond the annotations.

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 the core purpose, then uses structured blocks for return shape, coverage semantics, and examples. Every section adds decision-relevant information, and none feels redundant or padded.

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, but the description provides the JSON return shape, important coverage caveats, and realistic parameter examples. Combined with the fully documented parameter and safety annotations, an agent has what it needs to call the tool correctly and interpret the result.

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 input schema already fully documents the single `since` parameter, including type, pattern, default, and clamping behavior. The description's examples illustrate plausible values but do not add new parameter semantics beyond the schema, so the baseline score of 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?

The description states a specific resource and action: 'What changed in the Onchain Agent directory since a given date — additions, per-resource change events, and retirements.' It clearly identifies what the tool does and frames it for syncing. However, it does not explicitly distinguish itself from the similarly named sibling onchain_agent_recent_changes, so it stops short of full sibling differentiation.

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 gives clear usage context: 'Use this to keep a local copy in sync instead of re-fetching the whole catalog,' and advises periodic full re-pulls. No explicit when-not-to-use guidance or named alternative tool is provided, so it earns a 4 rather than a 5.

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