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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds value beyond that: it enumerates returned fields (name, account code, bank account number, inactive status) and states the auth requirement ('Cotlet API key with access to this app'). It doesn't cover rate limits or pagination, but with annotations handling the safety profile this is solid.

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?

Four sentences, front-loaded with the purpose before the downstream usage hint and auth note. Minor redundancy in restating 'Fiken: Bank accounts registered in the company' after the title, but nothing wasteful enough to penalize heavily.

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 carries the burden of describing return contents, which it does (name, account code, bank account number, inactive flag). It also covers the auth requirement and the creation limitation. Complete enough for a zero-parameter list 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?

There are zero parameters, so the baseline is 4. The description goes further by explaining the semantic role of the account code output field as the value to feed into register_invoice_payment and create_purchase, which is genuinely useful cross-tool context.

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?

States a specific verb (list) and resource (bank accounts registered in the company) and clarifies scope. It also distinguishes itself from siblings by noting 'Accounts are added in Fiken, not by this tool,' so an agent knows this is a read-only lookup rather than a create tool.

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?

Explains the practical purpose of the returned data ('Use the account code as bank_account in register_invoice_payment and create_purchase') and the precondition that accounts are managed in Fiken. There's no explicit when-not-to-use statement, but the usage context is clear enough to route the agent.

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