fetch_account_info

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

Annotations already indicate readOnly, non-destructive, idempotent. The description adds the return format (Account with id and currencyCode) and confirms safe frequent calls. Missing details like possible error cases or rate limits, but compensated by 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?

Three short sentences. Front-loaded with purpose, then usage guidance, then return format. No fluff, every sentence adds 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?

Given zero parameters and an output schema that is apparently not provided but mentioned in description, the description fully covers what the agent needs to call and interpret results. No gaps.

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?

No parameters in schema, baseline 4. Description adds meaning by detailing the return values (id, currencyCode), which is beyond the schema's empty definition. Provides concrete examples of currency codes.

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 it retrieves account metadata (currency and unique identifier). It uses specific nouns ('account metadata', 'base currency', 'unique identifier') and distinguishes from siblings that fetch other data like cash, orders, or pies.

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 says to use as a starting point before interpreting monetary values from other tools, and states it's safe to call frequently. This tells the agent when and why to invoke this tool over others.

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