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

Annotations already declare destructiveHint=true and idempotentHint=true, so safety is covered. The description still adds genuinely useful behavior: the favorites are private to the personal account, the 200-item cap, 'No bundle content is copied' (the bundle itself survives), and the no-store response caching. That is real context beyond the annotations.

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 action, followed by terse supporting facts. Every clause carries information, though the telegraphic fragment style ('Private to the personal account.') is slightly choppy.

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 single-parameter mutation with no output schema, the description covers scope, privacy, the cap, side-effect behavior, and response caching. Only the lack of alternative-tool routing keeps it from being fully complete.

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?

Single required parameter at 100% schema coverage, so the schema already documents the 'id' as a bundle ID from the public index. The description adds nothing about the identifier beyond repeating 'bundle', making the baseline 3 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?

States a specific verb and resource: 'Remove a bundle from your private favorites.' An agent can distinguish it from save_favorite from the verb alone, though the description does not name the sibling explicitly the way a 5 would.

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?

Usage is implied by the verb and by the 'Up to 200 favorites' constraint, but there is no explicit when-to-use/when-not guidance or pointer to save_favorite for the inverse operation. Adequate but with a clear gap.

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