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

Annotations already establish readOnly, idempotent, non-destructive, and closed-world behavior, so the bar is lower. With no output schema, the description usefully discloses what the caller receives (verified address/phone/website, fee, approved newspapers, e-filing system, forms), which is genuine added value; it does not cover miss/not-found behavior or caching.

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, zero waste: the first front-loads what is returned, the second front-loads when to use it and why. Nothing is repeated from the schema or annotations.

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 two-parameter, read-only lookup with no output schema, the description is nearly complete: it tells the agent the domain, the trigger condition, and the shape of the returned data. It lacks only edge-case behavior (county not found, unmatched county names) to be fully self-sufficient.

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% and both parameters (state, county) are documented in the schema itself, including accepted formats for state. The description only implies the county/state scoping and adds no format or matching nuance beyond the schema, 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?

States a specific verb ('look up') and resource ('SwiftProbate's published probate guide for a specific US county') and then enumerates exactly what the guide contains: courthouse contact info, filing fee, approved newspapers, e-filing system, and county forms. An agent can distinguish this from lookup_institution_guide purely from the county-court framing and returned field list.

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?

Gives clear triggering context — 'use this before answering any question about a county court's contact info, filing fees, or publication requirements' — plus a rationale (county details are unreliable from model knowledge). It stops short of naming a sibling alternative or stating when-not to use it (e.g., vs. lookup_institution_guide), so it does not reach the explicit-routing bar of a 5.

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