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

Annotations already declare the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=true). The description adds genuinely useful context beyond them: that the operation preserves the current mode and that it returns the resulting run-state. It doesn't detail side effects or permissions, but with annotations carrying that burden this is solid added value.

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 tight sentence front-loads the core action, embeds the key constraint, and a short second sentence states the return. No waste.

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-param, zero-required toggle with annotations already covering safety, the description covers purpose, the mode-preservation nuance, and the return value. Slightly thin on when-not-to-use guidance, but complete enough to invoke correctly.

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%, including a detailed `as` description covering multi-agent addressing. The description adds no parameter-level detail beyond the schema, so the baseline 3 for high coverage 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 pair (freeze/resume) and resource (the world), and adds a distinguishing constraint ('WITHOUT leaving the current mode') that separates it from mode-switching siblings. An agent can tell this is a non-destructive state toggle rather than a general 'play' or 'capture' action.

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 clear usage context — this is 'how you hold a moving scene still for a clean capture' — routing the agent to pair it with `capture`. It stops short of stating when-not to use it or naming explicit alternatives, so it's clear context without exclusions.

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