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

Annotations only cover safety (readOnly/idempotent), and the description goes well beyond them: it discloses the accuracy tier per state (exact schedule for CA/NY/NJ/IL/PA/GA/NC vs. a labeled effective-rate estimate with method: "estimate"), the tax-law sources, and the data vintage (Oct 2026). That kind of pre-call expectation-setting about approximation and provenance is exactly what an agent needs before trusting the output.

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?

The main purpose is front-loaded, which is good, but the rest is a very dense run-on packing bracket citations, statutory dollar constants, and wage-base figures into one block with no structure. Some of those numbers (Rev. Proc. 2024-40 / 2025-32, $15,750, $176,100) do not help an agent decide whether to call the tool and could be cut or deferred to output.

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?

There is no output schema, and the description compensates by saying it returns per-period and annual figures and by flagging the output's estimate labeling and local-tax gap. For a 9-parameter, multi-jurisdiction calculator this is nearly complete; only return structure detail (field names/shape) is missing.

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 coverage is already 100%, so the baseline is high, but the description adds real tax-treatment meaning the schema only partly captures: 401(k) lowering income tax but not FICA, HSA being FICA-exempt, and the PA/NJ quirks that tax 401(k)/HSA money. It leaves the state-code-format and gross-vs-gross-per-period disambiguation to the schema, which handles those fine.

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 and resource (calculates take-home/net pay) and pins the scope tightly: US employee, 50 states or DC, tax years 2025-2026. This clearly separates it from siblings like get_federal_tax_brackets (a lookup) and compare_states_take_home (a multi-state comparison).

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 implied by the scope statement (single paycheck, US, no local taxes) and it explicitly excludes local taxes like NYC, which is a useful when-not. But it never names the sibling tools or says when an agent should pick compare_states_take_home or get_federal_tax_brackets instead, leaving alternative-routing to inference.

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