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

Annotations already cover safety (readOnlyHint=true, destructiveHint=false, idempotentHint=true). The description adds valuable behavioral context beyond annotations by specifying that the tool 'Returns attribute rows (and geometry)', which clarifies the output format. It also mentions the sampling technique. No contradictions found.

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 long and front-loaded: the first sentence states the purpose and key parameters, the second provides a practical tip. Every sentence earns its place with zero waste. This is a model of concise, structured tool documentation.

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 tool has 6 parameters all documented with 100% schema coverage, so the description doesn't need to repeat parameter details. It does explain the return type (attribute rows and geometry) which is important since there is no output schema. The note about search_datasets gives workflow context. Missing some details like error behavior or rate limits, but these are less critical for a read-only query tool with rich annotations.

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%, so the baseline is 3. The description mentions the key parameters (where, out_fields, order_by, limit, offset) and gives a usage example, but it largely restates the schema. It does not add significant new semantics beyond what the schema already provides, so a 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'. The verb 'Query' is specific, the resource is identified, and the origin from search_datasets differentiates it from siblings like layer_info (which likely fetches metadata) and search_within (which likely performs spatial search).

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 for when to use the tool: to query a layer by URL, and it even gives a concrete usage tip ('Use where="1=1" + out_fields="*" to sample'). It implies usage in conjunction with search_datasets, but does not explicitly mention alternatives or exclusions, so I deduct one point for not explicitly differentiating from sibling tools.

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