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

Beyond the annotations (readOnly, idempotent, openWorld=false), it discloses a critical semantic trap: IsRatePermanent=true means 'no promo period', not 'fixed rate', and instructs how to present it to users. It also flags that verified data may be missing for some fields. This is exactly the kind of behavioral context annotations cannot carry.

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 purpose, then the return contents, then the IsRatePermanent caveat, then the empty-filter behavior. Dense but every sentence carries usable information; the IsRatePermanent paragraph is long but justified given its importance.

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 compensates by enumerating return fields (rates, fees, conditions, promo period, post-promo rate, eligibility, deadline). Combined with 100% schema coverage and read-only annotations, an agent has everything needed to call and interpret results correctly.

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 all six parameters (limit, sortBy, bankName, notConditional, minInterestRate, noCheckingRequired) are already documented in the schema with defaults and value semantics. The description only restates the default sort behavior, adding no syntax or format detail beyond the schema.

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 ('search and compare') plus a well-scoped resource ('savings accounts (konta oszczędnościowe) in Poland'), and enumerates what data comes back (rates, fees, conditions, promo details). The resource is distinct enough from siblings like SearchDeposits and SearchPersonalAccounts that an agent can route without opening the schema.

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?

Gives an explicit invocation default ('Call with no filters to get all accounts sorted by interest rate'), which tells the agent it is safe to call bare. It does not name alternative tools or when-not-to-use conditions, 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.