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

Annotations only declare readOnlyHint/destructiveHint; the description adds substantial behavioral context beyond that: 'Public, no auth', per-campaign-per-day point caps, the 50/50 revenue split, instant USDC payout with no settle day, and the push contract (label as 'sponsored', link url as given, report serves/recalls/clicks). This is rich, decision-relevant disclosure the schema and annotations do not carry.

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 definition is one sprawling run-on that interleaves the feed's content, the push contract, and payout mechanics; the actual answer to 'what does this return' is buried mid-sentence. Much of the payout/points material overlaps with what adnet_join, adnet_stats and adnet_report would more naturally own, so not every sentence earns its place here.

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 no input parameters and no output schema, the description does the heavy lifting by naming the feed's fields and stating the auth posture ('Public, no auth') and follow-up reporting obligation. It stops short of explaining selection/pagination or how to pick which placements to push, leaving a small 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 no parameters, so the baseline is 4; there is nothing for the description to disambiguate. It does list the fields returned in the feed (title, pitch, url, when, /word), which is helpful return-content context even though it is not parameter semantics.

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 identifies a specific resource — the live placements feed — and enumerates its fields (title, pitch, url, the `when` it fits, sponsor's /word), which distinguishes it from the mutation and reporting siblings (adnet_report, adnet_join, adnet_stats). However, the core sentence is a grammatical fragment with no main verb ('Every live placement … that a third-party agent may push'), so the agent must infer that this is a read of the placement catalog from context and the title rather than a clean statement.

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 scopes the audience ('PUBLISHERS'), states the precondition (run ads on your OWN surfaces), gives an exclusion ('nobody is paid for a post on X'), and routes the agent to the correct next tool ('REPORT what you did … with adnet_report'). It does not, however, explicitly contrast this feed against adnet_rounds or adnet_stats, so a bit of inference remains.

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