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

Annotations already declare the write/open-world/non-idempotent profile, so the description's real contribution is context beyond them: the account is free tier with no billing, creation is immediate, and a link_token is returned to claim the Idio login later. It omits failure modes such as captcha rejection or duplicate-email behavior, so not 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?

Three tight sentences, front-loaded with the action and its side effects, then the invocation trigger. No redundant restatement of the title or annotations.

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?

An output schema exists, so return values need not be explained, and the description usefully flags link_token anyway. However, for a five-parameter, non-idempotent registration tool with zero schema documentation, the missing parameter guidance and duplicate/failure semantics leave meaningful gaps.

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 0% and the description names none of the five parameters. While name and email are self-evident, captcha_token, use_case, and intended_tier carry real ambiguity (required format, when the token is mandatory, whether tier selection has consequences) that neither schema nor description resolves.

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 ("Register a free ColossalCapital account") and narrows scope to "a human user," which implicitly separates it from register_agent and register_org. An agent can identify the operation and target without opening the schema.

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 explicit triggers: call it when a tool returns account_required, or when a user asks to sign up. It does not explicitly say when to prefer register_agent or register_org instead, but the "human user" framing makes the split mostly inferable.

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