add_session

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

With no annotations provided, the description carries the full burden. It discloses the auto-creation behavior of the project and the conditional requirement for project_path. However, it does not mention idempotency, error responses, rate limits, or any side effects such as modification of existing data beyond creating the session.

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 consists of only two sentences, front-loading the main purpose and then adding the key conditional behavior. Every word is necessary and there is no redundancy.

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?

Given that an output schema exists (though not provided) and the schema covers 80% of parameters, the description is fairly complete. It covers the core creation behavior and the critical conditional logic. However, it lacks details on error cases, default values for optional parameters like actor_context, and any usage constraints (e.g., maximum sessions per project).

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 80%, so the baseline is 3. The description adds value by clarifying that project_path is required when the project is new, which the schema states but the description reinforces. It does not elaborate on actor_context, which is poorly described in the schema (just 'additionalProperties: true').

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 uses a specific verb+resource ('Create a new session linked to a project') and clearly distinguishes from sibling session tools like close_session and delete_session by stating it is for adding a new session, not modifying or deleting.

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 provides clear context for when to use this tool (adding a new session) and includes a conditional usage note about project_path for new projects. However, it does not explicitly state when not to use it or list alternative tools for similar actions like updating an existing session.

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