Login

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

Annotations declare readOnlyHint=false and destructiveHint=false, but description adds minimal behavioral context beyond 'Returns JWT tokens'. It does not mention session creation, token expiration, rate limiting, or side effects like invalidating previous tokens. Description does not contradict 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?

Single sentence is front-loaded with action and resource. No wasted words; every part adds value. Ideal conciseness for a simple tool.

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, description covers authentication action and return type. Could mention token expiration or storage format (e.g., 'JWT tokens' is sufficient but could be more specific). Overall adequate.

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?

Input schema has 100% coverage with descriptions for both parameters. Description repeats 'username and password' without adding meaning beyond schema. Baseline 3 is 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?

Description clearly states verb 'Authenticate' and resource 'Arcane using username and password'. It specifies return type 'JWT tokens', distinguishing from sibling auth tools like arcane_apikey_create (API key) and arcane_auth_refresh (token refresh).

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?

No explicit when/when-not or alternatives provided. Usage is implied as the standard login method, but without comparison to other auth tools (e.g., API key or OIDC) or mention of prerequisites like account existence.

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