crunchyroll_login

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

No annotations are provided, so the description must carry the full burden. It discloses that 'Tokens are saved locally for future requests,' which is a key behavioral trait (persistence and side effect). However, it omits details about error handling on invalid credentials, token expiration, or whether the tool sets session cookies. This is minimal but not misleading.

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 description consists of exactly two sentences with no unnecessary words. It efficiently conveys the core purpose and a key behavioral detail, earning its place without 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?

For a simple login tool with no output schema and no nested parameters, the description is fairly complete. It explains the action and the token persistence behaviour. Minor gaps exist, such as error handling or prerequisites, but overall it provides sufficient context for an AI agent to use the tool correctly.

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 100% with both parameters ('email' and 'password') having clear descriptions. The tool description does not add any additional semantics beyond the schema, meeting the baseline of 3.

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 clearly states 'Log in to Crunchyroll with email and password.' It specifies the exact action (log in), resource (Crunchyroll), and required credentials. This verb+resource combination uniquely identifies the tool among siblings, which are all content-related operations.

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 does not explicitly state when to use this tool versus alternatives. While it is intuitive that login is required before using other tools, there is no guidance on situations like re-authentication or handling expired tokens. No exclusions or when-not-to-use context is provided.

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