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

Since no annotations are provided, the description carries full responsibility. It discloses critical behavioral traits: the tool returns only swift and name per bank (not account numbers), country and currency are required and bound the result set, API key requirements, subscription tiers, strict daily caps (5/day PRO, 10/day VIP/FI/trial), and pagination limits (page 1–4). This level of detail ensures the agent understands constraints and side effects.

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 well-structured: a clear one-sentence summary, followed by a detailed explanation of behavior and constraints, then a bullet-like list of parameters with types and defaults, and finally concrete examples. Every sentence adds value; there is no redundancy or fluff. The front-loading of the core purpose and inverse relationship is effective.

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 the tool's complexity (6 parameters, cross-domain functionality) and the presence of an output schema, the description is complete. It explains the return format (swift and name only), required parameters, optional parameters, usage caveats (no account numbers), authentication requirements, rate limits, and examples. No significant gaps remain for an agent to invoke the tool 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?

With 0% schema description coverage, the description compensates fully. It explains each parameter: correspondent_swift with example 'IRVTUS3N', currency as ISO 4217, country as ISO 3166-1 alpha-2, name_prefix as optional prefix, page range 1–4, and api_key with alternative header options. It also emphasizes that country and currency are mandatory and bound the result set. Examples show parameter combinations, adding meaning beyond the raw 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?

The description explicitly states 'Reverse SSI lookup — find banks that use a given correspondent for a currency.' It clearly identifies the verb 'find', resource 'banks', and context 'using a correspondent'. It also distinguishes itself from the sibling 'ssi_lookup' by calling it the inverse, providing clear purpose differentiation.

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 explicit guidance on when to use this tool (reverse SSI lookup) and when not (for retrieving account numbers, it directs users to 'ssi_lookup'). It also details requirements: country and currency are required, an API key with specific subscriptions (PRO, VIP, FI) is needed, and daily caps are mentioned. Examples illustrate correct usage, making it highly instructive.

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