set_keyword

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

With no annotations, the description carries the transparency burden. It does disclose meaningful behavior: valid status values ('Active'/'Paused'), bid currency, and the partial-update semantics implied by 'and/or'. However, it does not mention permissions, reversibility, or side effects (e.g., overwriting existing values), which is a gap for a mutation tool without annotation coverage.

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 two sentences, front-loaded with the action, and every word adds value. The constraint is stated succinctly in a separate sentence. No redundancy or 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?

The tool has an output schema and a moderate number of parameters. The description covers the core update semantics and the required at-least-one rule, making it invocable. It lacks explicit alternatives or error conditions, but those are not essential for correct invocation given the clear schema and output schema.

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?

The schema coverage is 0%, so the description must compensate. It adds important semantics beyond the schema: the valid status values, that bid is in account currency, and the rule that at least one of status/bid is required. The required IDs (account_id, ad_group_id, keyword_id) are not explained, but their purpose is inferable from their names and the tool's function.

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 states the tool updates a keyword's status and/or bid, which is specific and distinct from sibling tools that modify campaigns or ad groups. However, it does not explicitly name alternative tools for other resource types, so it lacks the explicit sibling differentiation seen in higher-scoring examples.

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 provides an implicit usage context: update a keyword's fields. It also gives a key constraint ('Provide at least one of status or bid'), which is operational guidance. However, it does not explicitly state when to use this tool versus alternatives like set_campaign_status or set_ad_group_status, and offers no when-not-to-use guidance.

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