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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds behavioral context beyond annotations by specifying that it returns 'attribute rows (and geometry)' and supports 'SQL-like' querying, plus a sampling tip. It does not disclose pagination limits beyond offset/limit or rate limits, but with annotations present, this is sufficient.

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 two sentences, front-loaded with the core purpose, and includes a practical usage tip. Every sentence earns its place with no redundancy or 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?

For a query tool with 6 parameters and no output schema, the description provides essential context: what it queries (ArcGIS layer by URL), what it returns (attribute rows and geometry), and a sampling strategy. The link to search_datasets is helpful. It lacks explicit mention of response format, but the return description is adequate given the tool's simplicity.

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% (all 6 parameters have descriptions and examples). The description repeats parameter names (where, out_fields, order_by, limit, offset) without adding substantial new meaning. The sampling tip is useful but not a semantic explanation of individual parameters, so baseline 3 is appropriate.

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's function: 'Query an ArcGIS Feature Service / Map Service layer by its url'. It specifies the resource (Feature/Map Service layer) and the action (query), and distinguishes it from siblings like layer_info (which likely provides metadata) and search_datasets (which finds datasets).

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 description provides clear context: use this tool to query a layer by URL, and implies it follows search_datasets. It also includes a practical tip for sampling ('where="1=1" + out_fields="*"'). However, it does not explicitly state when not to use it or mention alternatives like search_within or layer_info.

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