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

With no annotations, the description carries the burden and does disclose meaningful behavior: it reports missing/unreadable values rather than silently succeeding, refuses to fabricate transactions, and will not default to EUR. What it does not define is what counts as a 'supported' transaction, which is the main behavioral unknown for a parser.

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?

Front-loaded with the core action, but the second sentence ('Use to extract supported transactions from actual pasted broker CSV or ledger text') largely repeats the first rather than adding new information. The requirement/error-handling sentence does earn its place.

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?

Output schema exists, so return shape needn't be described, and both required params are covered. The description gives the agent what it needs to call the tool safely; only the definition of 'supported transactions' is left open.

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 coverage is 100%, so both parameters are already documented in the schema, and the description's restatement ('Require the source text and actual base currency') adds no format detail or example. Baseline 3 applies since the schema does the heavy lifting.

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?

Names a specific verb and resource ('Turns pasted broker CSV or ledger text into analyze_portfolio transactions') and scopes it to 'supported transactions'. It is clearly distinguishable from the sibling parsers (parse_mortgage_statement_text, parse_pension_statement) and from analyze_portfolio itself, which it feeds.

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?

Explicitly states when to use it ('Use to extract supported transactions from actual pasted broker CSV or ledger text') and describes the workflow handoff ('Output rows can be sent to analyze_portfolio'), plus the preconditions (source text, actual base currency). It stops short of naming when NOT to use it or which sibling to pick for non-broker text.

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