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

Annotations already declare read-only and non-destructive behavior, and the description adds meaningful behavioral detail beyond that: hybrid lexical/embedding search with lexical fallback and the presence of ranked results with citations. It does not over-promise or contradict the annotations.

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 short sentences carry distinct, non-redundant information: what is searched, what is returned, and when to use it. The operation is front-loaded and there is no filler.

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 full schema coverage, safety annotations, and a present output schema, the description covers operation mechanics, result content, and a usage cue. It is nearly complete, but it does not help the agent choose between search_patterns and the very similar recommendation/list siblings, leaving some contextual ambiguity.

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 description coverage is 100%, so the schema already documents each parameter, which sets a baseline of 3. The description reinforces that the query targets a corpus and results are ranked, but it adds no parameter-specific meaning beyond the input schema.

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 the vendored Pattern-Assist corpus') and clarifies what the tool returns (ranked patterns with source_ref citations and optional when_not guidance). It is clearly distinct in practice from get_pattern and list_patterns, though it never names a sibling or states the contrast explicitly.

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?

'Use this before asserting an approach' gives a clear, directive context for when to invoke the tool. It does not mention when not to use it, nor does it point to alternatives such as list_patterns or recommend_patterns, so it stops short of full exclusion guidance.

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