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

Annotations provide only a title, so the description carries the burden of behavioral disclosure. It does mention that sessions persist cookies and localStorage, which is a key behavioral trait, but it does not disclose session expiration, resource implications, whether it returns a session handle, or any side effects beyond persistence.

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 a single, clear sentence that front-loads the action and key characteristics. It is concise, with no redundant or filler content.

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?

The tool has a simple interface with one optional parameter and no output schema. The description covers purpose and persistence behavior, but it omits how the created session is referenced in subsequent calls, which is crucial for using other tools with this session. The TTL parameter is only mentioned in the schema, not in the description.

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 single parameter 'ttl_seconds' is fully documented in the JSON schema with a description, default, and max value, so schema coverage is 100%. The description adds no additional meaning about the parameter; it only implies the session is stateful, which is not directly tied to the TTL.

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 verb 'Create' and specifies the resource as a 'stateful browser session' that persists cookies and localStorage. This distinguishes it from sibling tools like scrape_webpage or extract_metadata, which are read-only or extraction-oriented.

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 implies usage for scenarios requiring state persistence across multiple calls, but it does not explicitly state when not to use it or reference alternative tools. The context of 'across multiple scrape/workflow calls' provides some guidance, but no clear exclusions or prerequisites are given.

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