get_agent_run_checkpoints

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

Annotations mark read-only/idempotent, but the description adds meaningful context: checkpoints are persisted deterministic snapshots created at lifecycle transitions, and unknown run_ids fail with agent_run_not_found. This explains behavior beyond the annotation flags.

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?

Three focused sentences: purpose, sibling routing, then read-only/error/return behavior. Front-loaded and every clause adds value.

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?

For a one-parameter read-only tool, the description covers scope, error behavior, and return object at a high level. No output schema exists, but the description tells the agent what to expect and when to use it; annotations cover safety.

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 already covers the sole run_id parameter at 100% with guidance on where to obtain it. Description adds only the error condition for invalid IDs, so it does not need to compensate; 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?

States a specific verb and resource ('List persisted checkpoints of one agent run') and explicitly contrasts with sibling query_agent_run_checkpoints. An agent can identify exactly what this returns and how it differs.

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?

Directs agents to query_agent_run_checkpoints for cross-run searches, making the single-run vs across-run choice explicit. Also notes unknown run_id failure condition, adding operational guidance.

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