Your cost report

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

No annotations and no output schema, so the description carries the full disclosure burden. It does not say whose usage is reported (caller vs. account/org-wide), over what time period, whether the budget figure is per-user or shared, or whether the data is live or cached — all material for interpreting a cost figure.

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?

A single compact clause with no wasted words, and the most salient items (usage, cost, budget) lead. It is a fragment rather than a sentence, which slightly hurts readability but does not bury information.

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?

Because there is no output schema, the description reasonably lists the return categories — the minimum an agent needs. However, for a reporting tool it omits the scoping facts (time window, aggregation level, currency/units) and gives no way to distinguish it from get_cost_report-all, so it is only adequate.

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 tool takes zero parameters, so there is no parameter meaning to add; baseline 4 applies. The description at least enumerates what the caller receives, though that is a return-value concern rather than a parameter one.

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 the concrete data returned (token usage, estimated costs, cache efficiency, remaining budget), which is more specific than the title, but it is a noun phrase with no verb, so the agent must infer that this is a read/retrieval operation. It also gives no indication of how it differs from the near-identically named sibling get_cost_report-all.

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?

There is no when-to-use guidance, no prerequisites, and no mention of an alternative. With a sibling named get_cost_report-all in the catalog, the absence of any routing hint leaves the agent guessing which of the two to call.

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