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

readOnlyHint=true already establishes the safe-read profile, and the description adds meaningful behavioral value beyond it: the default filter posture, that visitor fees are only returned 'when known', and that booking fields appear only 'when the gym takes reservations' — non-obvious conditional return behavior.

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; the geographic scope and default filters are front-loaded and every clause carries information about either inputs or returns.

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?

No output schema exists, yet the description enumerates the return payload (drop-in policy, visitor fee, matching class times, reservePrice/reserveUrl) and states the conditional cases where fields are absent, so an agent knows both how to call it and what to expect back.

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 100%, so all six parameters are already documented, including their defaults. The description restates the drop-ins/today defaults without adding format or interaction 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+resource (find BJJ gyms) plus geographic scope (US city, neighborhood, or ZIP). It is clearly distinguishable in practice from get_gym or list_cities, though it never names a sibling to route against explicitly.

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?

Implies usage context by declaring defaults ('open to drop-ins, classes today'), which tells the agent what the unfiltered call returns, but gives no explicit when-to-use vs get_gym/list_cities guidance or when to override the defaults.

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