agent_resume

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

With no annotations, the description carries the full burden. It usefully discloses that the session restarts in the background under the same id, preserving identity, but says nothing about behavior if the session is already running, state loss, auth/permission needs, or error conditions.

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 tight sentences with zero filler, and the core action plus its background/same-id traits are front-loaded.

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 simple two-parameter resume tool with no output schema, the description covers the essential state transition and identity preservation. Minor gaps around failure modes and coexistence with a running session keep it just short of complete.

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 coverage is 100%, so both parameters are already documented. The description adds only that the message is optional and delivered 'on resume', which is marginal beyond the schema's own descriptions. Baseline 3 applies.

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 states a specific verb ('bring a stopped ... back') and resource ('Claude background session') with a clear-state precondition. It does not, however, distinguish itself from adjacent siblings like agent_respawn, whose name suggests a very similar restart operation.

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?

It implies when to use it ('stopped ... session') and notes the optional message path, but names no alternatives and gives no exclusions. An agent cannot tell from the text alone when to choose agent_resume over agent_respawn or agent_spawn.

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