check_login

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

With no annotations, the description carries the full burden and does disclose the return shape { loggedIn, currentUrl, message } plus the auth-failure handling, which is the key behavioral fact. It stops short of clarifying whether the check has side effects (e.g. launching the Chrome window if it is not running) or what latency/timeout to expect, leaving a real ambiguity for an unannotated tool.

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 short sentences: what it does, what it returns, when to call it and what to do on failure. Everything is front-loaded and nothing is redundant.

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?

With no output schema and no annotations, the description steps in to name the return fields and the false-login branch, which is sufficient to call and act on the tool. The only residual gap is that it does not say whether currentUrl is the page Chrome currently sits on or the expected timesheet URL.

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 tool takes zero parameters, so the baseline is 4. The description correctly says nothing about inputs and instead spends its words on return values and usage, which is the right allocation.

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: check whether the dedicated eHour Chrome is running and logged in. The 'dedicated Chrome window' scoping distinguishes it from generic browser or session tools and from the timesheet siblings it gates.

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?

Explicitly prescribes ordering ('Call this before apply_month/patch_day') and names the concrete failure branch ('if loggedIn is false, tell the user to sign in'). The agent knows both when to call it and what to do with each outcome, with the relevant siblings named.

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