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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuine behavioral context beyond that: the empty-input call returns an index of topics, and topic vs query select different lookup strategies. It is a knowledge read with no side effects, so no destruction/auth caveats are needed.

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?

Front-loaded with the returned resource, then the invocation modes, then the usage trigger. Three tight sentences with no redundancy or filler; every clause carries information an agent needs.

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 read-only lookup tool with no required parameters and no output schema, the definition covers content scope, invocation modes and usage trigger adequately. It could optionally note the maxTokens truncation behavior, but the schema already documents that parameter, so the gap is minor.

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 per-parameter documentation is already in structured data, giving a baseline of 3. The description goes further by explaining how the parameters interact and what happens when none is supplied (the topic index), which is not captured by the individual schema descriptions.

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 ('Returns') plus the exact resource (Better Design's sales principles) and enumerates the covered topics: objection handling, champion preparation, feature-to-value mapping. The 'sales' framing clearly separates it from sibling knowledge tools like get-ui-principle and get-ux-principle without needing to open any 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?

Gives explicit triggering context: 'Use it when the user prepares a sales conversation or writes a sales asset.' That is real when-to-use guidance, and the three invocation modes (topic / query / nothing) orient the agent further. It stops short of naming a sibling alternative or stating a when-not condition, so it lands just below the top.

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