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

Beyond the readOnlyHint/openWorldHint annotations, it discloses cost ("Free"), latency ("usually instant, a few seconds the first time"), a data-quality caveat ("+" when the map read was capped in a dense center), and an explicit scope boundary ("no crime figures, no safety rating"). It even points to the underlying method URL. That is meaningful behavioral context an agent cannot get from structured fields.

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?

Purpose is front-loaded in the opening clause, and later sentences carry distinct payloads (map cross-reference, latency, method link). The core sentence is long and heavily parenthesized, which costs some readability, but no sentence is pure 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?

There is no output schema, so the description must carry the return shape, and it does: it enumerates every returned fact and flags the capped-count notation. Combined with the cost, latency, and method disclosures, an agent has everything needed to call it and interpret the result.

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%, and the schema descriptions already explain that searchId comes from search_stays or get_stay and sourceId comes from the card. The description reinforces the "finished search" and "pick" framing but adds no format, constraint, or edge-case detail beyond the schema. Baseline 3 is correct.

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 names a specific resource and enumerates its contents precisely: counts of bars, pubs, cafés, restaurants and groceries within a ten-minute walk, plus the nearest stop and night-walking facts. That level of specificity makes the tool's scope unmistakable. It stops short of a 5 because it never names a sibling (e.g. get_stay, search_stays) to contrast against, so the agent must infer the boundary from context alone.

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?

"from a finished search" and "the pick's sourceId" imply the prerequisite state and inputs, which is useful implied guidance. However, there is no explicit statement of when to reach for this tool versus get_stay or city_picks, and no exclusion conditions. The agent can infer usage but is not told it.

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