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

Annotations already cover safety (readOnly, idempotent, non-destructive, openWorld), yet the description adds substantial non-obvious behavior: the live-drop license mechanism with 10% price escalation and 3-day window, null price meaning a use is unavailable, the human review and no-coordinate/no-exact-date privacy guarantees, and that each call consumes the daily read quota. This is well beyond what structured fields convey.

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?

Front-loaded with purpose, then moves to result shape, pricing, drops, and caveats — logical order with little wasted text. It is dense and runs long for a search tool, and the pricing/drop sentences could be tightened, but each sentence carries information.

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 fully carries the burden of describing returns (photo_id, preview URL, place breakdown, month, photographer, per-use prices) as well as the quota cost. An agent has everything needed to interpret results without opening a schema.

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 63% and the description adds real meaning: it explains why 'use' exists (pricing per use type), what ai_training actually filters on (photographer permission), and links place_id back to num_search_places. It does not clarify kind, limit, or offset beyond the schema, keeping it short of a 5.

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?

Opens with a specific verb+resource+scope: 'Search photos of real places taken by NUM travelers and offered for licensing per use.' This clearly separates it from the sibling num_search_places (places vs. photos) and from num_license_photo (search vs. purchase).

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 by the licensing framing and the place_id reference to num_search_places, but there is no explicit when-to-use/when-not or routing to the obvious follow-on siblings (num_license_photo, num_quote_photo). The agent must infer the search-then-license workflow.

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