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

Annotations already declare readOnlyHint and destructiveHint, and the description adds useful behavioral context: opening 'support' pops up the support chat, unknown destinations produce an error, and the agent should reply warmly and briefly. It doesn't contradict annotations and gives enough beyond them to score high, though it could mention any UI side effects more explicitly.

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?

Three compact sentences, each earning its place: purpose is first, then usage triggers and constraints, then the required response behavior. No filler or repetition; information is front-loaded and easy to scan.

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 tool with one required parameter, no output schema, and no nested objects, the description fully covers what an agent needs: when to use it, what it does, what can go wrong, and how to respond. Nothing is missing for correct invocation.

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 100%, so the schema already documents both parameters. The description adds value by illustrating the destination parameter with the actual value 'support', explaining the allowlist behavior, and warning that chatid is set automatically—semantics beyond the bare schema definitions.

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?

The description states a specific verb and resource ('Open an allowlisted place in the app') and immediately provides the concrete use case (opening support chat) with example phrases. It is distinct from any sibling tool—no other tool opens app destinations—and an agent can understand exactly what action this performs.

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 description gives explicit trigger conditions ('when they ask to reach a human or switch to support') with exact phrasing examples, and states the constraint that only allowlisted destinations work and unknown ones return an error to relay. This is clear when-to-use guidance with no ambiguity.

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