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

Annotations already cover read-only, idempotent, non-destructive and open-world, so the bar is lower; the description still adds that results are 'current' locations (implying no historical branches) and names the upstream source (FDIC BankFind institution locations), which helps the agent judge freshness and authority. It stops short of stating pagination/truncation behavior beyond the schema's limit default.

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?

Three sentences, front-loaded with the resource and field list, then filters, then routing. Every clause carries information — no restatement of the title or filler.

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?

A read-only list tool with a full output schema, no required params, and a clear data source; the description supplies scope, filterability, example queries and the prerequisite lookup path. An agent has everything needed to call it correctly on the first attempt.

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%, with each of the five parameters individually documented including the limit default of 50 and max of 500, so the schema carries the load. The description adds only the notion that filters are combinable ('and/or') and that name is used 'when cert is not known' — useful but marginal beyond the schema.

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 ('List the current branch and office locations of FDIC-insured banks') and enumerates exactly what each record contains, so the agent knows the payload shape before calling. The name-alone sibling fdic_branch_deposits is implicitly distinguished by the address/geo/service-type field list rather than deposits.

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 concrete filter combinations ('Filter by FDIC certificate number (CERT), bank name, state, and/or city') plus two natural-language example questions that map to real use cases. It explicitly routes the agent to fdic_search_institutions when only a name is known, but never contrasts itself with fdic_branch_deposits, the most likely source of confusion among siblings.

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