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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds only the 'Free with a PivotBank account' cost/auth context, and says nothing about processing time, page limits, or what happens with unsupported statements. Useful but thin beyond the annotations.

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?

A single well-formed sentence that front-loads the usage trigger and then lists the outputs. No wasted filler; the trailing pricing note is the only element of marginal value.

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?

With no output schema, the description usefully enumerates the returned analysis categories, and annotations carry the safety profile. It is nearly complete, lacking only edge-case behavior (unsupported PDFs, empty categories) for a nested-parameter tool.

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%, so both inputs (the statement object and pdf_base64) are already documented by the schema. The description mentions the 'bank statement PDF' but adds no guidance on when to use the file object versus the base64 fallback, so 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?

The description states a specific verb (summarise) and resource (bank statement PDF) and enumerates the outputs: money in/out, spending by category, top merchants, repeating payments. That is enough to distinguish it from convert_statement and list_supported_banks, though it never names the nearest sibling check_statement_balances, which also deals with statement figures.

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?

It gives an explicit triggering condition: 'Use this when the user wants to know where their money went from a bank statement PDF.' That is clear context for invocation. It offers no exclusions or alternatives (e.g., when to prefer check_statement_balances), so it stops short of full routing guidance.

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