Counts features in an ArcGIS Pro layer or table, optionally filtered by a SQL where clause.
Count features, optionally matching a where clause.
| Name | Required | Description | Default |
|---|---|---|---|
| where | No | SQL where clause. | |
| map_name | No | Map to act on; defaults to the active map. | |
| layer_name | Yes | Layer or table name as shown by get_layers, or a full dataset path. |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v1.1.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden, and it discloses almost nothing: no read-only/safety profile, no statement that counting avoids materializing geometries, no note on cost for large layers. The existence of an output schema covers return shape, but the description adds no behavioral context beyond the title.
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?
A single front-loaded sentence with no waste, and the optional-filter qualifier is placed correctly after the core action. It is efficient, though its brevity is partly under-specification rather than pure conciseness.
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 simple one-required-parameter count tool with a full output schema and complete parameter documentation, the description is minimally sufficient. It nonetheless omits any guidance on how this differs from other feature-reading siblings, which is the main gap given the crowded tool family.
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% – layer_name, map_name, and where are all documented in the schema, including the map_name default and the SQL nature of the where clause. The description merely echoes the where parameter, adding no syntax or format detail, 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?
States a specific verb and resource ("Count features") with the optional filtering scope, so the operation is unambiguous. It does not differentiate itself from siblings like get_features or summarize_features, which also operate on layer features, but the name plus description make the core action clear.
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?
The phrase "optionally matching a where clause" hints at filtering but gives no when-to-use guidance, no prerequisites, and no routing against get_features, get_field_statistics, or summarize_features. An agent must infer that this is the lightweight counting alternative to pulling full feature records.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.