Record a decision

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

Despite annotations all being false, the description explicitly discloses write side effects, append-only behavior, non-idempotency ('calling it twice records the decision twice'), and error conditions when the project or note is missing. It also says it never edits existing content, going well beyond the annotation fields.

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 description is three sentences: purpose, key constraint, and side effects/return/errors. It is front-loaded, concise, and every sentence carries essential information without redundancy.

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?

Even without an output schema, the description states what it returns (note path and heading) and when it errors. With all parameters documented in the schema and the tool's non-idempotent behavior explicitly disclosed, the description is fully sufficient for an agent to invoke this tool safely.

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 input schema already covers 100% of parameters with descriptions, so the baseline is 3. The description adds the Decision/Details format context but does not elaborate on individual parameter meaning beyond the schema.

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: 'Append a confirmed decision to a project's Decisions note' in a defined format. It includes the resource (project Decisions note), the operation (append), and a format constraint, making it distinct from siblings like append_rule.

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 gives clear context: use it only for confirmed decisions, and it warns about duplication on repeated calls. It does not explicitly mention when to prefer alternatives like append_rule, but the decision-vs-rule distinction is implicit.

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