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

Annotations already declare this a read-only, idempotent, non-destructive, closed-world lookup, so the safety burden is covered. The description adds real value by disclosing the shape of the returned record (department phone/hours/fax, mailing and overnight addresses, online notification URL, document checklist, probate-required account types), though it says nothing about coverage limits or what happens when an institution is not found.

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?

Single dense sentence with the verb and resource front-loaded, and the enumerated return fields follow in a scannable list. It is efficient, though the long parenthetical audience list and field roll-call make it heavier than strictly necessary.

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, so the description must convey the return contents, and it does so explicitly by enumerating the guide's fields. Combined with the clear single-parameter call contract, an agent has everything needed to invoke and interpret the result.

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 ('institution' and the optional 'category' hint) carry their own descriptions with examples, so the schema does the heavy lifting. The description adds no extra semantics about matching behavior (e.g., fuzzy name matching or what happens on ambiguity), 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?

Specific verb ('look up') plus a precisely scoped resource (SwiftProbate's estate-notification guide for financial institutions), with the target audience enumerated (banks, brokerages, life insurers, credit unions). It also lists the exact fields returned, so an agent can instantly distinguish it from siblings like lookup_county_guide or find_probate_forms without opening any schema.

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 audience and subject imply when it applies (you need contact/notification details for a bank, brokerage, or insurer), but the description never states when to prefer this over lookup_county_guide or find_probate_forms, nor any prerequisite like needing the estate's jurisdiction. Usage is inferable but not spelled out.

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