lichess_open

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

With no annotations, the description carries the full behavioral burden. It usefully discloses that the browser is signed-in and authenticated and that the URL defaults, but it omits what happens if a page is already open (navigate vs. new tab), whether existing page state is replaced, and what the call returns (snapshot, handle, or nothing).

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?

One well-formed sentence that front-loads the core action and follows with the concrete use cases. The phrasing 'to work with accept team join requests' is slightly awkward and could be tightened, but nothing is superfluous.

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 one-parameter browser-opening tool with no output schema and no annotations, the definition covers the basics but leaves important gaps: return value, behavior on repeated invocation, and whether the opened page persists for sibling tools to act on.

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% for the single optional url parameter and the description only repeats the default already documented in the schema. Baseline 3 applies since no additional meaning, such as accepted URL forms or path-only values, is added.

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 ('Open a Lichess page') plus the session context ('signed-in Cloud Browser') and default URL, which separates it from the read/click/type siblings that act on an already-open page. It never names those siblings explicitly, so differentiation is implied rather than stated.

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 hints at usage through the listed tasks (accepting team join requests, messaging a team), which implies this is the entry step before lichess_read/lichess_click/lichess_type. However, it gives no explicit when-to-use rule, no statement that a page must be opened before other tools work, and no when-not conditions.

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