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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds behavioral context by listing what is recalled (recent turns, checkpoints, open work), but does not disclose anything further like rate limits, filtering behavior, or how sessions are identified. No contradiction with annotations.

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?

A single sentence with no wasted words, front-loading the core action and scope. It is appropriately sized for a read-only recall tool with a well-covered schema.

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 tool has an output schema, fully described parameters, and annotations covering safety and idempotency, so the description's job is minimal. The only minor gap is that 'previous session' is ambiguous—how a session is identified is not stated—but the schema's current_session_id parameter hints at it, and the overall definition is sufficient for an agent to invoke the tool correctly.

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 100%, so the input schema already documents all six optional parameters. The description does not add meaning beyond 'recent turns,' which loosely maps to the n and time-range parameters, but it does not need to compensate for missing schema documentation.

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 ('Recall') and explicit resource ('where the previous session left off: recent turns, checkpoints, and open work'), making the tool's purpose immediately clear. It also distinguishes itself from the memory.* siblings by focusing on session continuity rather than general memory storage or search.

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 implies usage context: an agent should call this when it needs to resume work from a previous session. However, it does not explicitly state when to prefer this over memory.hybrid_recall, memory.search, or session.record, nor does it mention any exclusions or prerequisites.

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