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

Annotations declare a non-read-only, non-idempotent, non-destructive write; the description adds the non-obvious side effect that 'failed: true fails the run', which the annotations do not convey and which materially changes how an agent should call it. It does not, however, state whether the run must be open or what the call returns.

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 front-loaded sentence: the core action comes first, the illustrative examples follow, and the failure flag is tacked on last with no wasted words.

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 five-parameter mutation with no output schema and adequate annotations, the description covers the essential behavior including the failure side effect. It stops short of stating prerequisites (run must be in progress) or confirming whether notes are append-only, but nothing critical is missing.

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 60%; test and run_id carry their own schema descriptions, and the description explains the semantics of the otherwise-undocumented `failed` flag. The required `text` parameter and `address` gain nothing beyond the schema, so this sits at the baseline for partially documented schemas.

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 concrete verb+resource ('Adds a line of your own to a run') and immediately illustrates it with a real example ('Submitted the sign-up form'), which separates it cleanly from siblings like start_run and finish_run that bracket a run's lifecycle.

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 examples ('a step you took... or a failure of your own') imply usage during an active run, but the description never says when to reach for this versus finish_run or how it interacts with run state. Usage is inferable rather than stated.

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