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

With no annotations, the description carries the full burden and does well: it discloses the auth requirement ('Needs a Claycut key'), the cost profile ('free'), and the fallback behavior when nothing matches. It omits rate limits or whether matches are scoped strictly to the account, so it falls just short of full behavioral coverage.

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?

Three tight sentences with the purpose and the cost rationale front-loaded, followed by prerequisites and return shape. Every clause earns its place, including the return-value summary that compensates for the absent output schema.

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 one-parameter, read-only lookup with no output schema and no annotations, the description covers purpose, prerequisite, cost, the call-ordering with generate_app_icon, and the shape of returned fields. Nothing an agent needs in order to call it correctly is missing.

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 100% and the single parameter is already documented, including the 'omit to list recent icons' behavior. The description restates that behavior rather than adding new syntax, format, or matching semantics, so the baseline 3 applies.

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 and resource ('Find icons this Claycut account already generated or edited') with an explicit scope restriction to the caller's own account. It also differentiates itself from siblings by naming generate_app_icon and positioning itself as the prior step.

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?

Explicitly tells the agent when to call it ('Check here before generate_app_icon') and why (avoid paying for a new generation), plus the condition for the alternate mode ('omit to list recent icons'). The alternative and its selection condition are both named, leaving nothing to inference.

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