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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds a minor nuance ('most recent', 'today's') but no extra behavioral details like rate limits, authentication, or fallback behavior. It is consistent with annotations and sufficient for such a simple read-only tool.

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 a single, clear sentence that front-loads the action and result. No wasted words, ideal for a simple tool.

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 tool with one optional parameter, no output schema, and clear read-only annotations, the description provides enough context about what it returns (a joke). It doesn't describe output format, but the tool's purpose is obvious. A score of 4 reflects that it is nearly complete for its simplicity, though a bit more detail on the return could be added.

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 schema provides full documentation for the single 'lang' parameter, including enum values and default (vi). The description adds no additional parameter meaning, but since schema coverage is 100%, the baseline of 3 is appropriate.

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 it gets iFun's most recent joke, with a specific verb ('Get') and resource ('iFun's most recent joke'). It distinguishes itself from the sibling tool 'random_joke' by emphasizing 'most recent' and 'today's', making the purpose unambiguous.

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 the use case: when you want today's joke rather than a random one. It gives clear context about recency but does not explicitly name alternatives or exclusions, though sibling tools like 'random_joke' suggest the contrast.

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