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

With no annotations, the description carries the full burden. It adds 'Read-only', specifies searched fields, and documents the empty-query behavior. This goes beyond the schema, though it does not cover potential pagination or result ordering.

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 concise sentences with zero fluff. The primary purpose is front-loaded, and the special empty-query usage is tucked into a short second sentence. Every word earns its place.

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 search tool with 2 parameters and no output schema, this description covers purpose, scope, safety, and special behavior adequately. It does not describe the return format, but that is a minor gap given the simplicity of the operation.

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. The description adds meaningful extra semantics by naming the fields searched and clarifying the empty-query-with-tag behavior, which is not fully captured in the 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?

The description states a specific verb ('Search'), resource ('Spark catalogue'), and scope ('by keyword across app names, taglines, descriptions and tags, optionally narrowed to a single tag'). This clearly distinguishes it from siblings like get_app, list_apps, and list_tags without needing to open schemas.

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?

The description gives clear usage context: keyword search, optional tag narrowing, and the empty-query-with-tag pattern for listing everything under a tag. However, it does not explicitly mention alternatives or when not to use this tool, so it stops short of full exclusions.

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