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

Annotations declare readOnlyHint=false, destructiveHint=false and idempotentHint=false, so the safety profile is already carried by structured data. The description adds genuinely new behavioral context beyond that: the hide is presentation-only and the planner may still use the topic, plus the undo semantics. It does not mention permissions or persistence across sessions, so it stops short of a 5.

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 tight sentences: effect and scope first, reversal second, disambiguation from the sibling last. No restatement of the title, no filler, and the most decision-relevant constraint is front-loaded.

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?

With no output schema and only three parameters, the description covers what an agent needs: what is hidden, that the effect is presentation-only, how to reverse it, and which sibling to pick instead. Minor gaps remain around authorization requirements and whether the dismissal persists, but nothing blocking 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 67%: 'site' and 'label' are documented in the schema, but 'undo' has no schema description. The description compensates for exactly that gap by defining undo ('shows it again'), which is the one parameter the schema leaves bare. Remaining param details add nothing further, so 4 rather than 5.

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 ('Hide') and resource ('a research topic card from the plan's topic views') and immediately bounds the effect with '(presentation only: the planner may still use it)'. It also names the sibling it is not — exclude_topic — so an agent can distinguish the two without opening either 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?

Explicitly gives the alternative and the condition that selects it: 'To stop the planner from ever scheduling it, use exclude_topic instead.' It also documents the reversal path ('undo: true shows it again'), covering both directions of use.

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