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

With no annotations, the description carries the full behavioral burden, and it discloses almost nothing: no cutoff times, no holiday/weekend handling, no statement of how precise the 'estimate' is, and no return shape. Only the word 'estimate' hints that the result is approximate rather than guaranteed.

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 tight sentence with the purpose and both determining inputs front-loaded. No filler, no restating of the tool name, nothing that could be trimmed without losing 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?

No annotations, no output schema, and only 33% schema coverage for a 3-parameter tool. The description omits the amount parameter's role, cutoff-time rules, holiday/weekend behavior, and what the returned value looks like — an agent cannot call this confidently on edge cases.

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 33% (only submitted_at documented), so the description must compensate. It adds useful meaning for submitted_at ('submission time') and for the standard/same-day enum, but the amount parameter is never mentioned or explained, leaving one of three parameters semantically opaque.

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?

States a specific verb (estimate) and resource (US ACH payment settlement date) and names the two determining inputs (submission time, standard vs same-day). It is clearly separable from generic business-day siblings like add_business_days or is_business_day, though it never explicitly contrasts with them or with fx_spot_date.

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?

The 'given submission time and standard vs same-day' phrasing implies the conditions under which the tool is used, but there is no explicit when-to-use statement, no exclusion (e.g., not for FX or wires), and no routing to the analogous fx_spot_date sibling. Usage is inferable rather than stated.

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