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

With no annotations, the description must disclose behavior. It explicitly describes the self-healing mechanism: if session_id expired/closed, a fresh session opens and the response carries a new session_id and reopened:true. It also explains how repo/github/topic affect scope. This covers the main side effects, though it doesn't mention any potential data loss on the old session or auth/rate limits, which are not critical here.

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 sentences, front-loaded with the primary action. The first sentence is the core purpose; the second expands on self-healing and parameter usage. No wasted words; every sentence earns its place.

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?

An output schema exists, so return values are already covered. The description explains the self-healing behavior and parameter effects, which is sufficient for an agent to call this tool correctly. It doesn't define 'turn' explicitly, but role and content parameters make it clear. The description is complete for practical use.

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?

All 6 parameters have schema descriptions (100% coverage), so baseline is 3. The description adds meaningful context beyond the schema: it explains that repo 'preserves workspace scope and updates the state pointer', and that topic/github are 'used when reopening after expiry'. This extra context helps the agent understand the parameters' purpose, raising the score.

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 opens with a specific verb+resource: 'Append a turn to a working-memory session'. This clearly states the tool's action and distinguishes it from sibling tools like memory_session_open (which opens a new session) or memory_session_close (which closes one). The 'self-healing' hint further clarifies its niche.

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 explains when to use this tool implicitly by describing the self-healing behavior for expired/closed sessions and how to preserve scope via repo/github/topic. It also mentions avoiding a manual memory_state_set, which hints at an alternative. However, it doesn't explicitly compare with memory_session_open or state when NOT to use this tool, though the core usage is clear.

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