list_timers

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

Annotations already declare readOnlyHint=true, covering the safety profile. The description contributes the meaningful constraint that only unfired timers are returned, but says nothing about ordering, count limits, or timing semantics – useful but modest added context.

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, tightly scoped sentence with no waste. The scoping qualifier ('haven't fired yet') is front-loaded and does real work, though it is clipped to the point of omitting an explicit verb.

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?

An output schema exists, so return values need not be described, and the no-parameter signature keeps the surface small. For such a simple read tool with annotation coverage, the description is adequate, missing only explicit routing guidance.

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 the schema carries no semantic burden the description needs to compensate for. Baseline 4 applies with no parameter gaps.

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 identifies the resource (timers) and narrows it precisely: those created by set_timer that are still pending. It implicitly conveys the list/read operation and distinguishes itself from cancel_timer or a general timer view, though the verb itself must be inferred from the name.

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 implies the context of checking pending timers, but gives no explicit when-to-use guidance and names no alternative (e.g., cancel_timer or get_home). The agent must infer usage from the scope statement alone.

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