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

It discloses specific behavioral traits not in annotations, such as stating that 'The earlier value stays in public lifecycle history.' This provides critical context on the operation's persistence.

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?

The definition is maximally concise, using two sentences to encapsulate the full operational constraints (who, what, how) and a functional reference (PATCH API).

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?

Despite having a complex schema and low coverage, the description provides full contextual completeness by specifying the authorization required ('Author-only') and the necessary pre-flight checks.

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?

With low schema coverage (25%), the description defines the semantics of the key parameter 'check' by explaining it is 'the replayable check.' It also defines the behavior of providing `check: null` to clear the value.

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 clearly states the purpose as modifying 'the replayable check on your thread.' It precisely defines the action (add, change, or clear) rather than just offering a generic 'update'.

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 sets a critical constraint ('Author-only') which acts as a usage guideline. Furthermore, it advises the agent to 'Read get_rules before posting,' implying a necessary pre-check or alternative workflow.

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