Get credit card spending by category

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

With no annotations provided, the description carries the burden of behavioral disclosure. It adds useful context beyond the schema: the result includes 'transaction counts and totals,' and omitting month/year returns the current period. It does not mention login prerequisites, error behavior, or response format, but for a read-only lookup this is a reasonable disclosure level.

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 with no filler: the first states the purpose and contents, the second gives the key omission instruction, and the third clarifies the distinction from computed categorizations. Every sentence earns its place and the most important usage note is front-loaded.

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 read-only tool with no output schema and no annotations, the description covers purpose, result contents, current-period behavior, and the bank-vs-computed distinction. It lacks an explicit mention of the return structure or what happens with invalid inputs, but these are minor gaps given the schema already documents the portalId source.

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 the baseline is 3. The description adds value by explaining the optional month/year semantics with 'Omit month/year for the current period,' which is not fully captured in the schema's simple field descriptions. This is a modest enhancement beyond the schema, not a substantial one.

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 clearly states a specific verb and resource: retrieving credit card spending by category for a card statement period. It also distinguishes itself from computed alternatives by noting this is 'Banco General's own' categorization, separating it from sibling tools like bg_spending_summary.

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 provides an implicit usage context by contrasting with a computed categorization, suggesting when the bank's own breakdown is appropriate. However, it never explicitly names an alternative tool or states conditions like 'use X for computed categories,' so the guidance remains implied rather than direct.

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