Login to Iconfont

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

The description adds valuable behavioral context beyond the annotations: it specifies that the cookie is stored in memory only and lost on server restart, which clarifies the transient nature of the authentication. The annotations (idempotentHint: true, destructiveHint: false) are not contradicted, as login is typically idempotent and non-destructive. However, it doesn't detail rate limits or specific error conditions.

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 is well-structured with clear sections (purpose, args, how-to, returns, note, examples), making it easy to scan. It is appropriately sized, though the 'How to get the cookie' steps are somewhat detailed; every sentence serves a purpose, such as clarifying storage persistence and providing usage examples.

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?

Given the tool's moderate complexity (authentication with a single parameter) and the absence of an output schema, the description is mostly complete: it explains the purpose, usage, parameter, and behavioral aspects like storage limitations. However, it lacks details on return values beyond 'Success or error message,' which could be more specific, and doesn't cover potential error scenarios or authentication scopes.

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?

The schema description coverage is 100%, with the input schema fully documenting the single required 'cookie' parameter. The description adds minimal extra meaning by reiterating how to obtain the cookie in the 'Args' section, but this largely overlaps with the schema's description. No additional parameter insights are provided beyond what the schema already covers.

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 the specific action ('Authenticate with Iconfont using browser cookie') and resource ('Iconfont account'), distinguishing it from siblings like iconfont_check_login (which checks status) and iconfont_auto_login (which might use different authentication methods). It explicitly mentions accessing private projects and features requiring authentication.

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 provides explicit guidance on when to use this tool ('Login to access my private projects' in the examples section) and distinguishes it from alternatives by noting that for persistent login, the ICONFONT_COOKIE environment variable should be used instead. It also implicitly contrasts with iconfont_check_login by focusing on authentication rather than status verification.

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