open_and_read_url

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

With no annotations, the description carries the full burden and does well: it discloses that a background tab is created, that the user's real cookies/login sessions are used, and that the tab is closed afterward, so the agent knows no tab is left behind. It omits failure behavior, timeouts, and any rate-limit or permission caveats.

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?

Two sentences, no filler. The what/how sentence comes first and the when-to-use condition follows, which is the right front-loading for a tool selector.

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 read tool with no output schema, the description covers purpose, mechanism, scope conditions, and the return ('readable text'), which is everything an agent needs to select and invoke it 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?

A single required parameter whose schema description coverage is 100% and which needs no added syntax beyond 'http(s) URL'. The description adds no extra parameter meaning, but by the one-parameter/fully-covered baseline this is adequate.

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 (open/read) plus resource (URL), and names the mechanism (background Chrome tab using the real browser profile) and lifecycle (open, extract text, close). This implicitly separates it from read_active_tab, which observes a tab the user already has, without either schema being opened.

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?

Gives a clear positive-use condition: pages behind logins, session paywalls, or bot checks that defeat server-side fetchers. It does not, however, name read_active_tab or state when to prefer that sibling instead, so routing is left partly to inference.

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