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

Annotations already declare readOnlyHint/destructiveHint/openWorldHint, so 'Behavior: read_only' is redundant, but the description adds genuinely non-obvious context: workspace_id/user_id are injected from request headers, and a directive about presenting options when multiple records come back rather than acting on all of them. That multi-result handling guidance is behavior the annotations cannot convey.

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?

Front-loaded with the resource definition and organized into labeled Use when / Behavior / Returns sections, so an agent can scan it fast. Slightly inflated by the redundant 'Behavior: read_only' line (already in annotations) and a returns block that duplicates the output schema.

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?

Despite being a trivial zero-param read, the description covers everything an agent needs: what the vocabulary is, when to call it, that scoping is implicit via headers, the return shape, and how to handle multi-record results. An output schema exists, so the extra returns detail is bonus rather than a crutch.

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?

Zero parameters, so the schema baseline of 4 applies. The description still adds value by explaining that workspace_id/user_id come from request headers, pre-empting an agent's question about why no scoping parameter exists.

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 ('List the account categories') and immediately qualifies it as the fixed vocabulary with display labels, even giving example values (Customer, Prospect). This clearly separates it from the similarly named sibling get_workspace_categories and from the bulk_* mutation tools.

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?

Gives an explicit use case (populate a category picker) and names the three follow-up tools it precedes (BulkSetAccountCategory, BulkAddAccountCategories, BulkRemoveAccountCategories), which is strong routing. It stops short of stating exclusions against the confusingly similar get_workspace_categories sibling or any when-not condition.

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