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

Annotations already provide readOnlyHint, idempotentHint, and destructiveHint, but the description adds substantial behavioral context: the `{results, errors}` batch shape, the possibility of a `provider_incident` block, and explicit instructions that credit limits/balances may be unreliable and should not be presented as real. This goes well 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?

The description is front-loaded with the core purpose, then efficiently covers parameter bounds, batch response shape, and the provider incident caveat. Every sentence adds critical information, with no wasted words or repetition of annotation data.

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?

Despite having no output schema, the description explains the batch shape and the potential incident block, making the return behavior clear. It covers the essential constraints (array size 1–50) and reliability warnings, so the tool is fully usable without additional documentation.

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 coverage is 0% for the single parameter, but the description fully compensates by explaining 'Pass `account_ids` as an array (1–50)', adding the array size constraint and clarifying the parameter's role. This provides meaning beyond the bare schema definition of an array of strings.

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 the tool 'Returns full account objects including extended creditData (additional cards, limits) per id', with a specific verb and resource. It distinguishes itself from siblings like openfinance_list_accounts by focusing on per-id detail, and from openfinance_get_account_balance by mentioning extended creditData.

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 implies usage context: pass account_ids as an array (1–50) for batch detail, and the 'per id' wording suggests it is for specific accounts rather than a list-all operation. However, it does not explicitly name alternative tools (e.g., openfinance_list_accounts) or state when not to use it.

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