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

With no annotations, the description carries the full burden. It usefully clarifies that the tool is advisory ('says whether… and what to move to') and states the return shape ('a verdict and a rounded yearly margin'), but it omits safety profile, side effects, the required attribution source, and limits such as max held cards or data constraints.

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?

Two sentences, zero waste, and the purpose is front-loaded. The return-value note is compact and integrated naturally.

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 9-parameter tool with nested objects and no annotations, the description covers the core purpose and return shape but leaves important gaps: it does not disambiguate from sibling tools, does not mention required 'source' attribution, and does not state the advisory-only nature as explicitly as a no-annotation tool should.

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 the schema already explains all nine parameters thoroughly. The description adds only the redundant instruction 'Pass the cards as held' and a note about return values, without adding meaning beyond what the schema provides.

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 states a specific function: judging whether held cards still justify their annual fee and suggesting alternatives. It implies differentiation from siblings by focusing on 'cards the person already carries,' but does not explicitly name compare_two or simulate_cards to rule them out.

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?

It gives implied context ('cards the person already carries') and a direct instruction ('Pass the cards as held'), but offers no explicit when-to-use, when-not-to-use, or named alternatives among the sibling tools. The agent must infer that this is for existing-card evaluation rather than comparison or simulation.

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