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

With no annotations, the description carries the full burden and does so well: it discloses the energy cost (none), the action-slot cost, the 20-round respawn/despawn lifecycle, and two explicit non-effects ('nothing about this scores', 'does not touch your aggression counter'). An agent knows exactly what side effects to expect.

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?

Four short sentences, each carrying distinct information (precondition, cost, duration, non-effects), with the core action front-loaded. No filler or redundancy.

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-param, no-annotation, no-output-schema tool, the description covers preconditions, costs, duration, and side effects completely. The only omission is any hint of the return/confirmation format, which is minor given the tool's simplicity.

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 parameter exists (api_key) and schema coverage is 100%, so the schema fully documents it. The description adds nothing about parameters, which is acceptable at this baseline since no parameter requires behavioral interpretation.

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+resource ('Swat the resident fly'), which is clearly distinct from siblings like watch_fly and feed_fly that share the same target. It does not explicitly name those siblings, so the differentiation is inferable rather than stated.

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?

Gives a precondition ('It must be in your region') and the cost tradeoff ('costs no energy but spends your action slot'), which implies when the action is viable. However, it never contrasts against the obvious alternatives (watch_fly, feed_fly) or says when swatting is worthwhile versus pointless.

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