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

With no annotations, the description carries the burden. It implies a read-only search but does not explicitly state that it has no side effects or any access requirements. It does mention the return object, which provides some transparency about output, but lacks depth.

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 compact, with a single purpose sentence plus parameter and return documentation. It front-loads the main action and avoids unnecessary filler.

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?

For a simple one-parameter search tool, the description covers the purpose, parameter, and return. The presence of an output schema reduces the need to explain return values further, and the description is sufficient for basic usage, though it could mention error cases or alternatives.

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?

The description provides a detailed explanation of the 'identifier' parameter, noting it is the customer's unique identifier, typically the session_id. This compensates for the schema's lack of description for the parameter, though the slight inconsistency between session_key and session_id could be confusing.

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 a specific verb 'searches' and resource 'customer' using the identifier, and even specifies the return format. This distinguishes it from other customer tools like customer_create or customer_get_credit_balance, which serve different purposes.

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?

There is no explicit guidance on when to use this tool versus alternatives like customer_get_credit_balance or customer_allowance_workflow. The description only states the function, leaving the agent to infer the appropriate context.

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