open_session

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

With no annotations provided, the description must fully disclose behavioral traits. It states it returns a sessionId and implies session creation, but it does not mention side effects, idempotency, or what happens if the same sessionId is used twice. This is insufficient for a tool that likely persists state.

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 concise sentences: first states purpose, second explains namespace and return value. No unnecessary text. The structure is clear and front-loaded, though it could benefit from a bullet point or clearer separation of concepts.

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 description mentions the return value (sessionId) and its usage for subsequent calls. However, without an output schema, it should explain more about the session's lifecycle, such as the need to call close_session or whether sessions can be reopened. It is adequate but not complete.

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 input schema has 100% coverage with descriptions for both parameters. The description adds context about namespace deciding skill library reuse, which somewhat extends the schema's description. However, it does not add syntactic details, so baseline 3 is appropriate.

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 'open a scheduling session' and explains the role of namespace in reusing skill libraries. It distinguishes from siblings like close_session and decide_step, though it could be more precise about what a 'scheduling session' entails.

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 indicates when to use the tool: when you need to open a session with a specific namespace for skill reuse. However, it lacks explicit guidance on when not to use it or alternatives (e.g., if a session already exists, should you close it first?). The namespace explanation provides context but no exclusion criteria.

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