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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, and the description reinforces this with "Read-only." It adds valuable behavioral context beyond annotations by explaining the data provenance (daily snapshot time-series plus change-event log), the high-signal filtering policy, and the specific return shape including tone values. This is exactly the kind of transparency that helps an agent trust and interpret results.

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 dense but every sentence earns its place: purpose, scope switching, event examples, data provenance, filtering behavior, return contract, and a compact usage example. It is well-organized, front-loads the core purpose, and avoids filler despite covering substantial detail.

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 correctly provides the JSON return shape and tone semantics. It covers scope modes, event categories, filtering behavior, data sources, read-only safety, and example invocations. For a fully optional-parameter read-only query tool, nothing essential is missing for an agent to select and invoke it correctly.

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 the baseline is 3. The description adds compact usage examples like { days: 7 } and { slug: "coinbase-agentkit" }, but the underlying semantics for slug, days, limit, and response_format are already fully documented in the input schema. The description mostly restates rather than meaningfully extends parameter meaning.

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 clearly states a specific verb and resource: "Get recorded changes across the directory — the auditable Listing History." It also enumerates concrete event types and distinguishes site-wide versus per-resource scope, which makes the tool's purpose obvious. However, it does not explicitly differentiate itself from the sibling onchain_agent_get_changes, leaving some chance of tool-selection confusion.

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?

The description gives clear in-tool usage guidance: omit slug for the site-wide feed or pass slug for one resource's history. It also explains that passive drift is suppressed and that the tool is read-only. However, it never says when to prefer this tool over alternatives like onchain_agent_get_changes or onchain_agent_get_news, so the cross-tool usage context is missing.

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