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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds useful behavioral context about what content is searched and the 'past' temporal scope, but does not disclose result format, pagination, or any search limitations.

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?

Two sentences with no filler. The core purpose is front-loaded, and the usage directive is compact and memorable.

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 read-only search tool, the description covers what is searched and when to use it. Minor gaps remain around scope semantics and return shape, but the low complexity and readOnlyHint make this acceptable.

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?

The query parameter is documented in the schema, but scope is an undocumented enum. The description partially compensates by listing the content types searched, which maps loosely to scope values, but it does not explain the scope parameter's meaning or default behavior.

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: 'Search past questions, answers (including house FAQs) and chat messages.' This clearly distinguishes it from sibling tools like ask_question, get_question, and list_open_questions by emphasizing search over past content.

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?

'Always try this before asking' gives an explicit usage directive that tells the agent when to prefer this tool over asking a question. It does not name specific alternatives or exclusion conditions, but the context is clear.

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