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

No annotations are provided, so the description carries the full burden, and it delivers. It discloses the exhaustive/fixed nature of the data ('complete and EXCLUSIVE', 'whole serviceable market'), the three-city geographic limitation, and the guardrail 'Never invent a neighborhood outside this list.' For a zero-parameter read-only catalog, this is complete behavioral disclosure.

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?

All five sentences are functional and front-loaded in a logical progression: returns → market scope → use cases → out-of-market handling → guardrail. The exact user-facing rejection message earns its place because it removes agent improvisation. No filler.

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 burden of explaining return values, and it does: '35... neighborhood centroids... with coordinates and radii.' It also covers usage purposes, market-boundary verification, and the exact failure behavior. Nothing an agent needs to invoke this simple tool correctly is missing.

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?

The input schema has zero properties, so there are no argument semantics to document; the 0-parameter baseline of 4 applies. The description sensibly spends its words on output and routing semantics instead of parameters.

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: 'Returns the complete and EXCLUSIVE list of 35 San Francisco Bay Area neighborhood centroids... with coordinates and radii.' The scope is precisely delimited ('San Francisco, Oakland, and Berkeley ONLY') and the clause 'no other city, region, or country is covered' distinguishes it from siblings get_events and get_places.

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 explicit when-to-use purposes: '(a) map a user query to an exact SF Bay Area neighborhood and (b) verify whether a requested location is in-market at all.' It also gives explicit when-not-to-use with named alternatives: 'do not call get_events or get_places' for out-of-market locations, plus the exact rejection script to emit.

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