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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=true, destructiveHint=false). The description adds non-obvious behavior: results are returned newest-first and include titles, release dates, and support.microsoft.com URLs. It stops short of noting result-count limits or paging behavior, but the ordering guarantee is a genuinely useful addition.

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, no filler. Scope and when-to-use lead, and the fallback to get_kb_article closes. Every clause carries information an agent needs for selection.

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?

An output schema exists, so return values need not be re-explained, and the description still summarizes shape and ordering. Scope, usage condition, alternative, and query forms are all present for a two-parameter read tool.

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 baseline is 3, but the description goes further by enumerating acceptable query forms (topic, keyword, build, or KB number), which tells the agent it can pass '24H2' or 'KB5034441' as a query — semantic guidance the schema only hints at via one example.

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?

Specific verb (Search) plus a tightly scoped resource (official Microsoft KB articles for Windows 10/11/Server updates) and the queryable axes (topic, keyword, build, KB number). It is immediately separable from the sibling get_kb_article, which fetches a single article rather than searching.

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?

Explicit when-to-use clause: 'use for Windows update, patch, and known-issue lookups when you lack a KB number.' It also names the alternative (get_kb_article) and the condition that selects it, so the routing decision is fully specified.

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