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

Annotations declare readOnlyHint=true, so the safety profile is known. The description goes beyond this by disclosing the output format, the clustering algorithm (PostGIS ST_ClusterDBSCAN), per-event fields, and the active-only default filter. It does not mention pagination or rate limits, but for a read-only aggregation tool this is meaningful, useful behavioral context.

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 description is compact and front-loaded: the first sentence states the primary behavior and output format, with subsequent sentences adding clustering rationale, returned fields, and the default active filter. No sentence is redundant or wasteful.

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?

The description is sufficiently complete for a read-only, all-optional-parameter tool: it explains what is returned, what each event contains, and the default active-only behavior. Parameter details are covered by the schema, and the output shape is described even though no output schema exists. Minor gaps like exact filter semantics or pagination limits are not critical here.

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% with descriptions for all five optional parameters, so the schema already documents parameter meaning. The description adds no parameter-specific details such as value formats or interactions, so it stays at the baseline rather than adding extra value.

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 clearly states the tool 'Returns spatially clustered emergency events as a GeoJSON FeatureCollection,' naming a specific verb, resource, and output format. It also distinguishes itself from siblings like list_incidents and list_historical_incidents by emphasizing spatial clustering and the active-events default.

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 context is implied: the title 'incident intelligence' and the clustering language suggest this is for grouped incident views, not raw incident lists. However, there is no explicit when-to-use or when-not-to-use guidance, and no alternative tools are named, so the agent must infer the appropriate context from sibling names.

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