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

With no annotations, the description carries the full burden and does so well: it discloses that price/inventory is locked, that the hold is temporary and TTL-bounded, that no charge occurs, and that unsupported partners yield a structured fallback payload. It omits error/expiry behavior and any auth or rate-limit context, keeping it short of 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?

Three tight sentences with no filler, and the core action is front-loaded before the capability caveat and fallback. The 'PHASE 2 (API)' prefix is context-lite but not wasteful.

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?

For a 9-parameter, no-output-schema, annotation-free mutation tool, the description covers the essential behavior: what is locked, that nothing is charged, the partner-capability dependency, and the fallback path. It leaves hold expiry/failure handling unstated, which is a minor remaining 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?

Schema coverage is 78%, so the schema already documents most parameters (offer_id provenance, TTL bounds, quantity, principal_hints non-sensitivity). The description adds only the constraint that offer_id must come from a prior search response, which is already reflected in the schema; no additional semantics beyond the baseline.

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 (places a temporary hold), the resource (offer_id from a prior search), and the effect (locks price/inventory for a TTL). It also explicitly differentiates itself from geo360_book_offer by noting it 'Does not charge the principal', so an agent can distinguish it from siblings without reading the schema.

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?

Gives an explicit conditional route: use this when the partner supports api_hold, otherwise fall back to geo360_generate_affiliate_link. It does not spell out the relationship to geo360_book_offer (i.e., hold-then-book sequencing) or other when-not cases, so it stops short of full guidance.

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