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

Annotations already establish read-only, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds genuinely non-obvious behavioral context: the results contain callable snippets, 'how_to_use' should be sent as written, and new values are expected to work. It does not discuss the fallback path if the tool is absent beyond telling the agent to ask for a new chat, so it is strong but not exhaustive.

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?

Three tight sentences: identity first, triggers second, result handling third. No filler, no restatement of the title, and the most actionable instruction ('send how_to_use as written') is placed where it will be read.

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?

An output schema exists, so return-value detail is rightly omitted, and the one optional parameter is fully documented in the schema. For a simple read-only lookup the description is nearly complete; the only unaddressed point is what 'since' does to result volume and what happens when there are no updates in range.

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 coverage is 100% with a single optional 'since' date parameter already documented in the schema. The description never mentions date filtering or how far back updates extend, so it adds no meaning beyond the structured field. Baseline 3 applies when the schema does the work.

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 resource and scope: 'dated tool changes, each with the exact call to make.' This is a changelog/release-notes tool, clearly distinct from every listed sibling, which are market/wallet/portfolio data queries. An agent can identify what it 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 concrete trigger phrases ('update, catch up or what's new') plus a diagnostic trigger ('a Moby feature seems missing from your tools'), and even prescribes follow-up behavior depending on whether the referenced tool exists. It lacks an explicit when-not-to-use or a named alternative, so it stops short of a 5.

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