get_usage

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

With no annotations, the description carries the full behavioral burden and does meaningful work: it discloses the return contents and a non-obvious edge case, that credits_limit and period_reset_date are null for one-time credit grants. It does not cover permission requirements, response size, or whether per-user breakdowns are paginated, which keeps it from a 5.

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?

Two sentences, front-loaded with the verb and resource, followed by the return inventory. The parenthetical listing credit field paths is dense but earns its place by conveying a null-semantics rule. Slightly over-packed, but there is no filler.

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?

For a single optional-parameter, read-only reporting tool with no output schema, the description carries the necessary return-value explanation well, including the credit fields and their null behavior. The structure of per-user breakdowns and search counts is left unstated, a minor gap given there is no output schema to consult.

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%, with the month parameter fully documented including the YYYY-MM pattern and the omit-for-12-months default. The description merely restates that filtering by month is optional and adds no format or default detail beyond the schema, so the baseline 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 names a specific verb and resource ("Get API usage data") and then enumerates the payload: search counts, per-user breakdowns, and the IQ credit balance. That is enough for an agent to distinguish it from the surrounding search/agent-run siblings, none of which report usage or credits. It stops short of explicitly contrasting with a sibling, so it lands at 4 rather than 5.

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?

Usage is only implied: an agent should call this when it needs usage or credit information. "Optionally filter by month" hints at the one scoping decision available, but there is no explicit when-to-use or when-not-to-use guidance and no mention of alternatives. For a read-only reporting tool with no competing sibling, this is adequate but thin.

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