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

Annotations already declare read-only, idempotent, non-destructive, closed-world behavior, so safety is covered. The description adds genuinely useful behavioral context beyond that: brownfields are reported points rather than parcel boundaries, and results do not constitute a clearance determination. It does not quantify result volume or the effect of the limit parameter, but the key semantic caveats are disclosed.

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 short sentences, front-loaded with the action and scope, followed by two precise limitations. Every sentence earns its place; the only minor inefficiency is that the 10 km cap duplicates the schema maximum.

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 an output schema present the description need not document return values, and annotations cover the safety profile, so the remaining burden is scope and limitations, which are handled well. The notable gap is run_id, whose purpose and relationship to a prior call are never explained.

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 0% across five parameters, so the description carries the burden and largely does not meet it. It explains radius_km as a proximity window but merely restates the 10 km maximum already encoded in the schema, and says nothing about limit, run_id, or the latitude/longitude pair beyond 'reference point'.

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?

Uses a specific verb ('Screen') with a specific resource ('mapped environmental layers') and states the spatial scope (reference point plus nearby cleanup locations within radius_km). It is distinguishable from siblings like get_parcel_terrain or get_site_context, though it never names an alternative directly.

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 negative guidance ('not full-parcel overlap, contamination or environmental clearance'), which tells the agent what this tool must not be used to conclude. However, it offers no positive when-to-use routing versus the many related context tools (get_site_context, get_parcel_terrain, get_regional_energy), leaving the agent to infer selection.

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