list_countdowns

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

No annotations are provided, so the description carries the full behavioral burden, yet it discloses nothing beyond the verb: no indication of whether all countdowns are returned, how they are ordered, whether results are paginated, or whether any user/permission context is required. For a read-only tool this is low risk, but the disclosure is still absent.

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?

A single short sentence with no filler and the verb-resource pairing front-loaded. It is efficiently sized, though its terseness is a symptom of under-specification rather than deliberate economy.

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?

With no output schema, no annotations, and no parameters, the description is the only source of information, yet it says nothing about what a returned countdown looks like or whether the list is filtered or sorted. For a zero-param list tool the description is technically usable but leaves the return contract entirely unspecified.

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 tool takes zero parameters, so there are no parameter semantics to document; per the baseline for 0-param tools this scores 4. Schema coverage is vacuously complete.

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 verb and resource ('Lists countdowns') that an agent can parse, and the Chinese gloss (倒数日) disambiguates the resource as day-countdowns rather than a timer. However, it is essentially the tool name restated, with no scope, ordering, or filtering detail, so it barely clears the minimum-viable bar rather than distinguishing itself from the many sibling list_* tools.

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 guidance on when to call this versus alternatives such as list_tasks, list_habits, or list_calendar_events, nor any prerequisite or exclusion. The agent must infer usage purely from the name.

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