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

Annotations already cover readOnly, idempotent, non-destructive, closed-world, so the safety profile is handled. The description adds non-annotation value: the cost signal ('Free'), the conceptual shape of the response (preferences plus excluded-creator count), and the opt-in behavior of include_excluded_emails. It omits any mention of pagination behavior despite limit/cursor existing, which is the main remaining gap.

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?

Four tight sentences, front-loaded with what is returned, then the parameter hint, then the usage trigger, then the cost note; every sentence carries information. Parentheticals are dense but not padded.

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?

No output schema exists, so the description must convey return content — and it does, naming the preference fields and exclusion count. With 5 params including limit/cursor, the absence of any pagination note is the one substantive omission; otherwise complete for a simple read tool with full annotation coverage.

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 80%, with include_excluded_emails being the one undocumented parameter — and the description explicitly explains what it does (lists excluded emails, i.e., creators already worked with). That is exactly the compensation needed. It adds no extra detail for uid/limit/cursor, but the schema already documents those.

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?

Specific verb 'Read' plus a precisely scoped resource: the user's saved Agent Preferences, with the two key contents enumerated (default creator criteria, whether email-less creators are accepted) and the exclusion count. This is clearly distinguishable from update_preferences and from the search/discovery siblings it influences.

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 triggering condition: 'Check this when results look unexpectedly narrow,' which links this read to debugging search outcomes. It also implicitly separates the read path from update_preferences, but it doesn't state exclusions (e.g., don't call this to change settings, or that it isn't needed before every search).

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