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

The annotations already declare the tool read-only, idempotent, and non-destructive. Beyond that, the description adds valuable behavioral detail: it uses SOD data, groups non-MSA branches under 'Non-MSA / Rural', sorts markets by deposits, and includes summary counts. This significantly exceeds what annotations alone provide.

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 description is well-structured with a leading purpose sentence, a bulleted output list, and a closing note about rural branches. It is concise, scannable, and every line contributes meaningful information without redundancy.

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?

Given the context signals include an output schema and helpful annotations, the description still provides essential additional context: data source, grouping behavior, sorting, and output categories. It fully covers the tool's behavioral scope for an agent to select and invoke it correctly.

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%; both 'cert' and 'year' are described in the schema itself. The description does not add parameter-level meaning beyond restating that the data is SOD-based, so it stays at the baseline for full schema coverage.

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?

The description opens with a specific verb ('Analyze') and a precise resource ('geographic franchise footprint ... using Summary of Deposits (SOD) data'). It clarifies the output as a market-by-market breakdown of branches, deposits, and percentages, which distinguishes it from sibling tools like fdic_market_share_analysis or fdic_get_institution.

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 description implies usage—when you need to see an institution's geographic footprint and deposit distribution across MSAs—but it does not explicitly state when to use this tool over alternatives or mention any exclusions. Clear context is present, but there is no direct comparison or 'use when...' guidance.

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