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

Annotations cover the safety profile, and the description adds substantial operational context beyond them: a hard cap of 10 results, nearest-first ordering, the returned fields (city, distance in miles, machine count, venue kind, url), the meaning of `searched` (city centre vs venue-placed smaller cities) and `note` (nearest anywhere vs nearby), plus a data-freshness caveat that machine lists from Pinball Map can lag.

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?

Dense but front-loaded: purpose and example queries come first, then input formats, then return shape and caveats. Every sentence carries distinct information, with no filler or repetition of the schema.

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 and no nested objects, the description carries the return-value burden itself and does so fully: count, ordering, fields, url usage guidance, the semantics of `searched` and `note`, and a staleness caveat. An agent has everything needed to call this correctly and interpret the response.

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 the baseline is 3, but the description adds interaction semantics the schema does not: `country` matters only for postal codes outside the US, and `game` accepts either a display name or a slug. That clarifies how the parameters combine rather than merely restating them.

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 and resource: finds pinball venues near a place, optionally filtered to a machine. The opening example queries and the 'pinball bars in Portland' phrasing make it instantly distinguishable from siblings like search, search_pinball_games and get_pinball_stats.

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 concrete routing examples for natural-language intents and states when to pass `game` (name or slug) and what `place` accepts (postal code vs city), including the country-code requirement for non-US postal codes. It does not explicitly name a sibling as the alternative for overlapping lookup needs, 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.