session_add_turn

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

There are no annotations, so the description carries the full burden of behavioral disclosure. It clearly indicates a mutating operation ('append') and identifies the target as the session's fast cache, but it does not disclose side effects, persistence, whether the fast cache is the same as session history, or any capacity limits. This is a significant gap for a write operation with no annotation support.

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, dense sentence with no filler. The role list is efficiently packed into a parenthetical, and the resource and action are front-loaded. It is appropriately concise, though the brevity does contribute to incompleteness—a concern that belongs to contextual completeness rather than conciseness.

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 four parameters with zero schema descriptions, no annotations, and no output schema, the description is too terse to be fully actionable. It does not state whether the session must already exist, how the fast cache relates to the session's main history, or what the optional dataset parameter is for. An agent would have to guess at important context for a mutating session operation.

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 must compensate for undocumented parameters. It does provide the allowed role values (user/assistant/tool/system), which aids the 'role' parameter, but it leaves 'session_id', 'text', and especially the optional 'dataset' unexplained. The description adds only partial parameter meaning.

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 identifies a clear verb (append), a specific resource (a turn to the session's fast cache), and enumerates the accepted role values. This differentiates it from reading tools like session_get or session_timeline and from session_set_context, which sets context rather than appending a turn. The jargon 'fast cache' introduces slight ambiguity, preventing a perfect 5.

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 siblings such as session_start, session_set_context, or remember. There is no mention of prerequisites like an already-started session, nor any exclusions or alternative conditions. Usage context must be inferred entirely from the action verb.

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