Discounted vendors

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

Annotations already declare readOnly/idempotent/openWorld/non-destructive, so the safety profile is covered. The description adds a genuinely useful behavioral caveat: the campaign is curated, so results are a strict subset of discounted vendors, plus that discount_pct is vendor-wide rather than per-item. It doesn't cover pagination behavior, but the schema does.

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 the tool's scope before the routing hint and the placement caveat. Every sentence carries information: the campaign identity, the use case, the unit of discount_pct, and the sibling trade-off.

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 read-only listing tool with 100% schema coverage, the description is adequate, and it surfaces a result-shape detail (discount_pct) that has no output schema to hold it. The only gap is pagination/return-structure detail, which the page_size schema note partly covers.

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%, so all five parameters are already documented (lat/long bounds and examples, page, sort enum, page_size with its page-1 quirk). The description adds no syntax or format detail beyond the schema, so the 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?

States a specific verb (list) and resource (vendors in the 'Food Shots' discount campaign) with the locality constraint ('near a point'). It names the sibling relationship to tf_restaurants explicitly, so an agent can distinguish the two without opening schemas.

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 the concrete user intent it serves ('which restaurants have the biggest discount') and the explicit alternative plus its trade-off ('tf_restaurants with discounted_only is wider'). When-to-use and when-to-prefer-the-alternative are both present.

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