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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, so the safety profile is clear. The description adds context about the return type ("attribute rows (and geometry)"), the SQL-like query semantics, and the sampling shortcut, which enriches the behavioral model beyond the annotations without contradicting them.

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?

Two crisp sentences pack the core purpose, source relationship, available parameters, return type, and a practical sampling example. No filler words. The opening verb makes the tool's action immediately understandable, and all content earns its place.

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 well-documented parameters and no output schema, the description is highly functional: it specifies the source data type, the parameter set, the return payload (attribute rows + geometry), and a helper tip. It does not detail the default limit or pagination behavior, but these are already in the schema, so the overall package is complete enough for an agent to operate.

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% and every parameter has a detailed description (url, limit, where, offset, order_by, out_fields). The description repeats parameter names but does not add semantics beyond the schema, such as data type nuances or interaction effects (e.g., how offset interacts with limit). Baseline 3 is appropriate because the schema does the heavy lifting.

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 opens with a specific verb and resource: "Query an ArcGIS Feature Service / Map Service layer by its url (from search_datasets)." This clearly distinguishes it from sibling tools like search_datasets (which finds datasets) and layer_info (which presumably describes layer metadata), while also stating the exact function.

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 "from search_datasets" indicates a prerequisite workflow, and the tip "Use where="1=1" + out_fields="*" to sample" provides concrete guidance. However, it does not explicitly state when not to use this tool or name alternative tools for different operations, so it falls just short of the 5-level bar.

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