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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false, openWorldHint), so the bar is lower. The description adds genuine value beyond them by disclosing the data's provenance (Daily Treasury Statement), its daily cadence, and the units of the values (millions of dollars) — all traits an agent cannot get from the structured fields.

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 tightly constructed sentence that front-loads the resource and appends provenance and units as clarifying parentheticals. Every clause earns its place; nothing is padding.

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 low-complexity, single-parameter read-only tool with no output schema, the description covers what the data is, where it comes from, and its units. It only omits how results are shaped or paginated, which is a minor gap given the annotations and simple schema.

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?

There is a single optional parameter (`limit`) and the schema description coverage is 100%, so the schema already documents it fully. The description adds nothing about pagination, row counts, or the limit parameter, so the baseline 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 resource (the US Treasury's daily operating cash balance / Treasury General Account) and its source, so an agent can immediately tell it apart from other treasury_* tools like auctions, debt, or rates. It stops short of explicitly naming sibling tools, but the resource is distinctive enough that no differentiation is needed.

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: explaining that this is the government's checking account at the Fed tells an agent what the data means but not when to prefer it over treasury_debt or treasury_interest_rates. There are no exclusions, prerequisites, or alternatives named.

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