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

Annotations already declare readOnly, idempotent, non-destructive, so the safety profile needs no restating. The description adds that suggestions refresh daily and each carries a reason, which is useful context, but says nothing about how many are returned, whether they expire, or what acting on one does. Modest value beyond structured fields.

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?

A single sentence, front-loaded with the resource and provenance, then parenthetical examples. Every clause 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?

With an output schema present and annotations covering behavior, the description only needs to convey source and content, which it does. A brief note on the relationship to decide_ad_suggestion would close the last gap.

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 tool takes zero parameters, so there is nothing for the description to disambiguate; baseline of 4 applies.

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?

States a specific resource (open ad suggestions) and its origin (Siren's daily review), with concrete examples of suggestion types. It distinguishes itself from mutation siblings like decide_ad_suggestion implicitly through the word 'open', but never names a sibling 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?

Usage is implied: call this to see what Siren recommends. There is no explicit when-to-use/when-not, and no pointer to the natural follow-up tool (decide_ad_suggestion) or to ad_performance for raw data. Letting the agent infer the workflow from 'open suggestions' is adequate but thin.

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