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

readOnlyHint=true already tells the agent this is a safe read. The description adds useful scope context with "All categories are team-created," implying a complete, small, shared set with no user-specific categories. It does not address pagination, rate limits, or auth requirements, so it adds moderate value beyond the annotation.

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 short sentences plus a brief scope note; the purpose and the returned fields are front-loaded, and nothing is padded or repeated from the title.

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 read-only list tool with one well-documented parameter and no output schema, the description covers purpose, usage, scope, and even the shape of the returned objects. Nothing an agent needs in order to call it correctly is missing.

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% and the lone property parameter is fully documented in the schema, including the pointer to list_properties. The description adds nothing about the parameter, so the baseline 3 for schema-does-the-work 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 (List) and resource (annotation categories) and even enumerates the returned fields (IDs, names, colors, icons), which separates it from get-custom-annotations and get-recent-annotations by resource type. However, it never names or contrasts those siblings explicitly, so it falls short of full sibling differentiation.

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?

"Use this to discover available categories before filtering annotations by category" gives a clear when-to-use trigger and a natural workflow position. No exclusions or alternatives are stated, but the context is unambiguous.

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