share_of_search

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

The annotations already establish read-only, idempotent, open-world, non-destructive behavior. The description usefully adds scope and output behavior: up to 4 competitors, share over the whole range, start/end fifth values, and change in points. It does not cover auth or rate limits, but the annotation coverage lowers that burden.

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?

The description is front-loaded with the core definition, then adds rationale, return details, and one input-resolution rule. It is readable and mostly earns its length, though the return-detail sentence is partially redundant because an output schema exists.

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 an output schema present, the description need not detail return values, yet it does. It still omits meaning for several optional parameters and provides no sibling differentiation, leaving an agent with gaps despite adequate coverage of the core brand/competitor use case.

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 0% across six parameters. The description clarifies that brand can be a topic id resolved via find_topic and that competitors may include up to 4 brands, but it leaves geo, category, property, and timeframe unexplained.

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 clearly defines the tool as computing a brand's share of search against up to 4 competitors and how it moves. It states the specific metric and scope, though it does not explicitly distinguish itself from sibling analytical tools such as keyword_overview or compare_many.

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?

It provides one concrete usage rule — use topic ids via find_topic when a brand name has other meanings — and implies the tool is useful as a leading market-share indicator. However, it gives no explicit when-to-use or when-not-to-use guidance relative to the many sibling trend tools.

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