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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, yet the description adds real extra context: the personal-account requirement, the 200-item cap, that no bundle content is copied, and the private/no-store response caching. Only the response shape (ID format) is left unspecified.

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?

Five short front-loaded fragments, each carrying a distinct fact (scope, prerequisite, limit, content behavior, caching). "Private to the personal account" partially restates the account requirement, a minor redundancy.

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?

With no parameters and no output schema, the description covers the essentials an agent needs: it is a personal-account read of IDs, capped at 200. The only gap is the concrete return format of the ID list, which is minor for a parameterless read.

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?

The tool takes zero parameters and the schema has 100% description coverage, so there is nothing for the description to clarify. Baseline 4 applies with no compensating burden.

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 names a specific verb and resource ("List your favorite bundle IDs") and the ID-only scope implicitly distinguishes it from the sibling favorite_bundles. It never names favorite_bundles explicitly, so the agent must infer the split from the word "IDs".

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?

It states a prerequisite ("Requires a personal account"), which is genuine usage guidance, but gives no explicit when-to-use vs. favorite_bundles / save_favorite / remove_favorite routing. Usage is only implied by the scope of the returned data.

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