stats

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so 'Makes no network calls' largely restates the closed-world hint. The one genuinely additive signal is 'roughly', which tells the agent the figures are approximate and not billing-grade. No further behavioral context (e.g. what 'saved' is measured against) is given.

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 short sentences, with the substantive content (what is reported and over which time windows) front-loaded. The trailing 'Makes no network calls' is the weakest clause since annotations already convey a closed-world read operation, but the overall size is appropriate.

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 an output schema present, rich annotations, and no parameters, the description only needs to state what the report covers — which it does, including the time buckets and the approximation caveat. The remaining gap is the lack of differentiation from the 'status' sibling.

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 semantics burden; the schema is empty and nothing needs compensating. Baseline 4 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 concrete verb ('Show') and a concrete resource (token and money savings attributed to Deputy), plus the scopes reported (session, today, 7 days, all time). It does not, however, distinguish itself from the sibling 'status', which an agent could reasonably assume overlaps with a stats/savings report.

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 infers it should call this when it wants a savings summary. There is no explicit when-to-use/when-not statement and no reference to the alternatives (status, review, investigate), so the routing decision is left to the reader.

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