pin

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

With no annotations provided, the description fully carries the behavioral burden. It discloses idempotency, replica queueing behavior, refusal conditions for items that cannot carry a binding, and the possible reply strings. This is unusually complete for a tool description.

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?

Every sentence in the description carries a distinct, useful behavioral fact. It is dense but not bloated, and the most important purpose is front-loaded before edge cases and alternatives.

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 description is complete for a tool with no output schema and no annotations. It covers the normal success outcome, the no-op case, replica behavior, refusal cases, and the alternative tool, leaving little for an agent to guess.

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?

The schema already covers the only parameter id with 100% coverage and a clear description. The tool description reinforces that the item is existing, but does not need to add more because the schema handles parameter semantics fully.

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 action: adds the Always binding to an existing item, and clarifies the effect ('served in full at every session start'). It also distinguishes the tool from revise by name, so an agent can tell what pin does without inferring from the name alone.

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 explicitly says to use revise instead when anything besides the binding needs to change, which gives clear routing between sibling tools. It also covers the already-pinned case, replica behavior, and refusal cases, so an agent knows when the operation will not behave as a normal write.

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