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

Annotations already cover read-only, idempotent, open-world, non-destructive, so the safety profile needs no restating. The description adds value beyond them: it states this is a marketplace listing that includes budget, and that responding happens out-of-band through the a-un agent API rather than through this tool. It says nothing about result volume, pagination, or freshness.

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, front-loaded with the resource and its scope, then the usage condition and next step. No filler or restated 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?

With no output schema, the description compensates by indicating results carry budget and job details, and it names the out-of-band reply mechanism. It leaves open how many listings return or whether results are paged, which is the remaining gap for a no-arg listing tool.

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 100% and the single optional 'category' filter is fully documented with an enum in the schema. The description never mentions filtering, so it adds no semantic value over the schema — baseline 3 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?

Specific verb + resource + scope: 'List open jobs that people posted on the a-un marketplace', with a clarifying gloss ('I want an agent') and the returned content (budget and details). It does not explicitly name the reverse-direction sibling find_agent_services, so an agent must infer the distinction from 'people posted' vs. services offered.

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?

'Use when your agent sells a service and wants paid work' gives a concrete usage condition, and the follow-up path (reply with an offer via the a-un agent API) is stated. No explicit when-not guidance or named alternative tool, so it stops short of a 5.

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