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

Annotations already cover the safety profile (readOnly, non-destructive, openWorld), so the description doesn't need to. It adds genuinely non-structured behavior: a per-platform credit table by scale, the price-quote-before-run rule, background execution, and the instruction to follow error.fix and surface billing.display on error. Some of this overlaps the `confirm` and `max_cost_credits` schema text, which keeps it from a 5.

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?

The purpose is front-loaded in the first sentence, followed by cost, then error handling — a sensible order. The credit table is dense but each figure is decision-relevant for scale selection. A tighter phrasing of the confirm/background sentence would have made it a 5.

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 nine-parameter, cost-incurring, potentially background-executing tool with no output schema, the description covers the things an agent cannot infer: pricing tiers, quote-before-run behavior, and error recovery. What's missing is only the boundary against sibling creator tools, which is the one gap keeping it from 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?

Schema description coverage is 100%, so every one of the nine parameters is already documented in structured form, including the nuanced `confirm` tri-state and `handle` reuse semantics. The description adds no parameter meaning beyond that, so the baseline 3 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?

The opening sentence names a specific verb-like operation (find creators on one platform for a niche) and enumerates the return content: size, recent posts, fit score, and reasons. An agent can distinguish this from single-creator siblings like creator_card or user_profile. It stops short of explicitly naming those siblings, so it lands at 4 rather than 5.

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?

The description gives real operational context — price-first quoting for costly/long runs, background execution, and the free `handle` re-read path that avoids a re-run. But it never states when to prefer this over siblings such as creator_card, search, or user_profile, leaving the alternative-selection decision to inference from names alone.

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