write_note

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

Beyond the readOnly/destructive/idempotent annotations, the description discloses that failed conditions suppress the write and report the actual stored value. It also clarifies the guard semantics and the mutually-exclusive condition rule, which annotations alone do not convey.

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?

Four short sentences, each carrying distinct information: the operation and limit, the two optional guards, the exclusion rule, and the failure output. Nothing is redundant or padded.

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 write tool with no output schema, the description covers the key behaviors an agent needs: durability, size constraint, conditional guards, mutual exclusion, and error reporting. Namespace/key constraints are already fully covered by schema descriptions.

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?

Although schema coverage is 100%, the description enriches the guard parameters substantially: it explains exactly when if_matches and if_absent permit writes, the one-condition restriction, and the failure reporting behavior. This goes well beyond the schema's 'Compare-and-set guard' labels.

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 opens with a specific action and object: 'Write a durable note', with an explicit length cap. The conditional semantics further define variants of this write operation, and 'durable' distinguishes it clearly from transient sibling tools like say.

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 gives clear context for conditional use: use if_matches for compare-and-set, if_absent for create-only, and explicitly forbids sending both. It does not explicitly enumerate sibling alternatives, but the durable/write framing makes the intended use evident.

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