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

Beyond the readOnly/idempotent annotations, the description discloses the actual privacy mechanism (grid snapping, no pin, shaded circle guaranteed to contain the true point, identical output per grid cell) and closes the obvious re-identification attack by noting the point cannot be averaged out across listings. It also states the return shape (inline image plus reusable URL containing only the snapped point) and the cost: 'Counts 1 static image against the account's monthly cap.'

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?

The privacy guarantee is front-loaded in the first two sentences, then usage, then return/cost. It is slightly dense in the second sentence, but every sentence carries information an agent would otherwise have to guess.

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 10-parameter image tool with no output schema, the description covers purpose, mechanism, privacy guarantees, return format, URL behavior, and billing cost. Nothing material is missing for an agent to decide whether and how to call it.

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 explains every parameter including snap_deg and radius_m. The description adds conceptual reinforcement of snapping but no new per-parameter semantics, 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 opens with a specific action and effect: render 'roughly where a place is without revealing the exact point', which cleanly separates it from an exact-point static map. It never names the sibling static_map explicitly, so an agent must infer the contrast from the privacy framing, which keeps it just short of a 5.

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 gives concrete when-to-use guidance: 'real-estate, rental and marketplace listings, people's homes, or any location that should stay private.' It does not state the inverse rule (use static_map when the exact point is acceptable), so the alternative-selection guidance is implied rather than explicit.

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