decrease_brightness

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

Annotations already declare destructiveHint=false, readOnlyHint=false and openWorldHint=false, so the safety profile is covered. The description contributes the relative-step model and default of 5 percent, but says nothing about boundary behavior (clamping at 0 or 100) or whether the change is immediate/persistent.

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?

One sentence, front-loaded with the action and resource, with the parameter default folded in economically. Nothing extraneous.

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 one-optional-parameter, no-output-schema tool with full schema coverage and annotations covering safety, the description is essentially sufficient. Only the edge-case behavior at brightness limits is missing, a minor gap.

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?

Schema description coverage is 100% and the single 'step' property is already documented as 'Percentage to decrease (default 5)'. The description restates that same information rather than adding meaning, so the baseline 3 applies.

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 ('Decrease screen brightness') plus the magnitude semantics ('by N percent'), which cleanly separates it from increase_brightness, set_brightness, and get_brightness in the sibling list. An agent can select it without opening the schema.

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?

Usage is only implied by the verb: the agent can infer this is a relative adjustment rather than an absolute set, but the description never explicitly says to prefer set_brightness for a specific target level or increase_brightness for the opposite direction. No exclusions or preconditions are stated.

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