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

With no annotations, the description carries the full burden and does substantial work: it explicitly denies execution, payment, fund reservation, settlement, and proof creation, and declares fail-closed behavior on unknown price, max cost, or rights. It also flags the authentication requirement. It does not say whether a plan artifact is persisted or what the response contains, which keeps it off a 5.

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 tightly packed sentences with no filler, and the planning-only constraint is front-loaded. Density is high enough that undefined domain terms ('A2A', 'VUO/adoption proof') cost some readability, but nothing is redundant.

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 behavioral contract is well covered for a mutation-adjacent planning tool with no annotations. However, with no output schema and 0% parameter coverage, the description leaves return values and three of four inputs unexplained, which is a real gap for an agent composing a call.

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 partly does: 'maximum cost' and 'unknown price ... fails closed' relate to requester_max_price, and 'rights' gestures at qualification. The required 'need' parameter, 'currency', and 'candidate_identifier' are never explained, leaving most inputs undocumented.

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 verb+resource: a planning-only route to qualified external A2A supply, which an agent can distinguish from execution-oriented siblings like economic_preflight or get_economic_operation. The jargon ('A2A supply', 'VUO/adoption proof') is not defined, so the resource is clear only to an agent already familiar with the domain.

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?

No guidance on when to call this instead of the many adjacent siblings (discover_external_agents, match_need, economic_preflight, pre_spend_preflight). 'Planning-only' hints at a pre-execution stage, but the agent must infer the sequencing itself.

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