session.set_mode

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

With no annotations at all, the description carries the full burden of disclosing behavioral traits. It only states that it 'updates' the mode, implying a mutation, but does not explain side effects, reversibility, permission requirements, or how it affects other session operations. This is a significant gap for a state-changing tool.

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 sentence with no wasteful words, and it is front-loaded with the action. However, it is overly sparse given the complexity of the tool, and the lack of structure (e.g., separating what each parameter does) makes it less useful than it could be. It is concise but at the expense of substance.

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 is incomplete for a tool that mutates session state, especially with no annotations, no output schema, and no parameter descriptions. It does not explain what 'safety/determinism mode' means, the effect of each parameter, or what the tool returns. The presence of related tools like session.mode increases the need for clearer context.

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 0%, so the description should explain the parameters. It mentions 'safety/determinism' which hints at read_only and deterministic, but does not explicitly map them or clarify the required session_id. The description fails to compensate for the lack of parameter documentation in the schema.

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 the verb 'Update' with the resource 'session safety/determinism mode', making it clear that this tool modifies an existing session's mode. It distinguishes itself from session.mode (which likely reads/gets the mode) by indicating a change operation. However, the phrase 'safety/determinism mode' is somewhat vague and could be more explicit about what aspects are affected.

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?

No guidance is provided on when to use this tool versus alternatives like session.mode or when it is appropriate to change these settings. The description gives no context on prerequisites, typical use cases, or situations where this tool should be avoided.

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