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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so safety is covered. The description adds genuinely useful behavior beyond that: this returns a change-log style feed (cuts, increases, newly added models) rather than a point-in-time price table, which is not derivable from 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?

One efficient sentence with no filler, and the core scope is front-loaded. However, the single run-on phrase bundles two distinct result types (price changes and newly tracked models) without structural separation.

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 conveying returns and does so partially by naming the two result categories. But it leaves the default 90-day window, the limit cap, and the min_change_pct threshold semantics completely unexplained, which is a real gap for a 3-param tool.

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 only 33% — only 'since' is documented. The description does not mention limit, min_change_pct, or the 90-day default behavior at all, so it fails to compensate for the undocumented parameters.

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?

Names the resource (official list-price changes and newly tracked models) and the specific semantic scope (cuts/increases observed in daily snapshots). It differentiates from list_llm_prices by being a change-event feed rather than a current-price listing, though it never states this contrast explicitly.

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?

No guidance on when to call this versus list_llm_prices, get_price_index, or the other sibling list tools. No mention of defaults, pagination, or result ordering, so the agent must infer usage entirely.

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