read_statement_header

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

With no annotations provided, the description carries the full burden. It discloses that the tool is read-only (only reads the header block), avoids loading operation rows, and behaves as a lightweight preview. This is meaningful behavioral information beyond what the schema conveys, though edge cases like error handling or return format are not addressed.

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 a single, tightly written sentence with no filler. The main purpose is front-loaded, the content scope is enumerated concisely, and the behavioral caveat ('without loading the operation rows') earns its place by clarifying what the tool does not do.

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 simple one-parameter read tool with no output schema, the description is sufficiently complete: it names the file type, the fields contained in the header, and the typical usage intent. It stops short of describing the exact return format, but the listed fields give the agent a solid expectation of what will come back.

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 the single parameter file_path is already well documented as 'Absolute path to the mBank CSV file'. The tool description adds no extra detail about the parameter, so the schema carries the weight and the baseline of 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?

The description states a specific verb ('Read'), a precise resource ('header block of an mBank CSV export'), and enumerates the exact content (client name, date range, listed accounts, inflow/outflow totals). It also distinguishes itself from operation-focused siblings by explicitly saying it does not load operation rows.

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 phrase 'Fast preview to confirm you have the right file' clearly establishes the intended use case: verifying file identity before deeper processing. It implies that when operation rows or summaries are needed, the sibling tools list_operations and summarize_operations would be appropriate, though it does not name them explicitly.

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