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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuine context beyond them: the data provenance (city open data), the result ceiling of 10, and the shape of the returned payload (distance plus opening times or equipment). It omits edge behaviour such as empty results or invalid locations, keeping it just short of a 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?

One dense, front-loaded sentence covering resource, scope, result cap and return contents, followed by a compact invocation example. No filler, no restatement of the title, and the most decision-relevant information comes first.

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 only two fully documented parameters and no output schema, the description must carry the return-value burden, and it largely does (distance, opening times or equipment, max 10 items). What remains unstated is failure behaviour and whether results are sorted by proximity, a minor gap for a tool this simple.

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 already enumerates 'kind' and gives the exact 'near' examples ('Jordaan', '1017', 'Dam 1') that the description repeats. The only added meaning is the inline example pairing kind='toilet' with near='Jordaan', which is useful but mostly duplicative, 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 names a specific verb and resource ('nearest public toilets or playgrounds'), scopes it geographically ('to Amsterdam neighbourhood, postcode or address'), and states the data source ('city open data'). It also pins down the result cap ('up to 10'), which lets an agent distinguish this from any generic search sibling.

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?

Usage is implied by the domain rather than stated: the tool is self-evidently for finding nearby facilities in Amsterdam, and no sibling tool overlaps it. There is no explicit when-not-to-use guidance or prerequisite statement (e.g. what happens with an out-of-city address), so it sits at the implied-usage level.

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