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

Annotations already declare this is a non-readonly, non-destructive, non-idempotent, closed-world action, so the safety profile is covered. The description usefully confirms the state change is energy gain and adds the Chill-specific depth nuance, but says nothing about cooldowns, limits, or failure modes.

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?

Front-loaded trigger and effect in one compact line with a concrete example. The leading 'Pet Rest.' restates the title and is the only wasted token.

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 zero-required-parameter state-mutating tool with a documented output schema, the description covers purpose, trigger, and outcome. Missing only edge-case behavior such as energy caps or cooldown, which is minor here.

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?

Only one optional parameter (key) and the schema documents it at 100% coverage, so the baseline is 3. The description adds nothing about the key, though the 'pet_rest {}' example usefully signals the call can be made with no arguments.

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 ('rest your pet') plus the effect ('energy up'), which separates it from siblings like pet_play, pet_feed and pet_clean. It does not name an alternative tool explicitly, so it falls just short of a 5.

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 'WHEN:' clause gives an explicit trigger for calling it, and the parenthetical notes that Chill rests deepest, a useful selection nuance. There is no explicit when-not guidance or named alternative, so it stops at 4.

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