guard_login

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

Annotations already declare openWorldHint=true and idempotentHint=false, so the bar is lower. The description adds real substance beyond that: the call returns a link and short code immediately without blocking, completion is deferred to a second tool, and the resulting token is scoped by account role. It does not say where the token is stored or whether it expires, which keeps this 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?

Three sentences, each load-bearing: what the tool does and its style, what it returns and what the user must do, and the follow-up call plus run-once-per-machine rule. The critical immediate-return behavior is front-loaded.

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?

There is no output schema, so the description must carry return-value semantics, and it does — an immediate link plus short code, with the authorization step delegated to guard_login_check. Combined with the sibling hand-off and reuse note, an agent has everything needed to drive the flow 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 description coverage is 100% with a single optional 'scope' parameter whose default and meaning are fully documented in the schema. The description adds no additional syntax or format guidance for scope, so the baseline of 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?

States a specific verb and resource in plain terms ('Começa o login no HOC Guard') and immediately anchors it to familiar analogues (npm login / gh auth login). It is clearly distinguishable from siblings guard_login_check (step 2) and guard_logout, which the description names or implies.

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?

Explicit sequencing: run this first, show the user the link/code, wait for browser authorization, then call guard_login_check to complete. It also states the frequency constraint ('uma vez por máquina') and that downstream tools (guard_scan_site, generators, purposes) reuse the session automatically, so the agent knows when NOT to call it again.

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