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

With no annotations, the description carries the full behavioral burden, and it does disclose a meaningful trait: cost (1 credit per call). However, it does not say whether the operation is deterministic, whether duplicates are removed or merely reported, whether output is idempotent, or what happens when the 500-keyword cap is exceeded.

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, zero waste: the primary purpose and its three sub-operations are front-loaded, and the cost line is short and independently useful. Nothing is repeated from the name or title.

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 two-parameter, no-output-schema transform tool, the description is nearly complete: it states inputs, outputs, and cost. The remaining gap is output shape (how match types and duplicates are returned) and the undocumented enum values, which the schema leaves entirely bare.

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%, so the description must compensate, and it only partially does. It implies the keywords input and gestures at the intent/negatives_for parameter, but never enumerates the five allowed intent values (none, b2c_services, ecommerce, software, jobs_filter) or explains the 80-char/500-item limits.

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 names a specific verb+resource ('Turn a keyword list into Google/Microsoft Ads match types') and enumerates three concrete outputs: match types, duplicate detection, and a negative-keyword starter list. No sibling tool (ad_copy_check, ad_metrics, utm_builder) overlaps with this keyword-formatting job, so an agent can route to it unambiguously.

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?

Usage is implied by 'for a chosen intent,' which hints that negatives_for should be set deliberately, but there is no explicit when-to-use, when-not-to-use, or alternative-tool guidance. Nothing tells the agent whether this replaces or complements ad_copy_check or ad_metrics.

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