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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint, so the safety profile is covered structurally. The description adds genuinely new behavioral detail beyond that: the return payload is neighborhood ids, and stations that are planned or under construction are flagged in the output. It does not cover pagination or result-count behavior, keeping it below 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 front-loaded sentences with no filler; the scope definition leads and the return contract follows. Minor redundancy: the enumerated place types duplicate what the 'place' schema field already says, costing a little density.

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 carries the return-value burden and does so by naming neighborhood ids and the planned-station marking. For a 4-parameter read-only lookup whose schema is fully documented, that is nearly complete; only result limits or error behavior remain unstated.

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 schema already documents every parameter including the 800m default and the transaction_type semantics. The description's place-type list largely restates the schema's own 'place' description rather than adding syntax or format guidance, 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?

The description gives a precise verb+resource+scope: the neighborhood containing a place plus those within walking distance. It also enumerates the accepted place kinds, so an agent knows exactly what input domain is covered. It does not, however, differentiate itself from the sibling neighborhood_context, which is the most likely confusion.

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?

It supplies clear context for use — 'Returns neighborhood ids you can pass to search_listings' establishes the workflow position and downstream consumer. It stops short of stating when NOT to use it (e.g., versus neighborhood_context) or any prerequisites, so no explicit alternative routing.

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