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

Annotations already declare readOnlyHint=false and destructiveHint=false. The description adds the relative adjustment context and that current level isn't needed, but doesn't disclose additional behavioral traits like failure modes or side effects. Since annotations cover the safety profile, a 3 is appropriate.

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 that front-loads the core action and constraint. No fluff, every word earns its place.

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 simple two-parameter tool with annotations, the description is adequate. It explains the relative nature and delta range, but doesn't explicitly differentiate from set_volume. That gap is minor, so a 4 is warranted.

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 coverage is 50%, with delta lacking a description. The description compensates by explaining delta as a relative amount (-30 to 30) and that current level isn't needed, but doesn't specify units or semantics beyond that. This adds some value over the schema.

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 (raises/lowers) and resource (room's volume), with the relative nature distinguishing it from set_volume. It's not a tautology and clearly communicates the tool's function.

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?

Mentions that it's a relative adjustment and that current level isn't needed, implying it's for when a relative change is desired. However, it doesn't explicitly name the alternative (set_volume) or state when not to use it, so it's clear but not fully explicit.

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