PM Playbook

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

The description discloses determinism ('returns the same operating guide as plain text every call'), explicitly confirms no side effects, and details the content (grounding, spine, prioritisation, done). This adds meaningful behavioral context beyond the annotations, which already indicate read-only and idempotent. No contradictions.

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 two sentences, front-loaded with the tool's purpose, and every clause adds value—covering no-args, deterministic output, content summary, and usage timing. No filler or repetition.

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 deterministic, no-argument guide, the description fully covers what the tool returns, what topics it addresses, and when to use it. There's no output schema, but the description's content summary is sufficient for an agent to understand the return value. It's a complete description for this simple tool.

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?

Since the schema has zero parameters, the baseline is 4. The description confirms 'No arguments,' which is consistent with the schema and removes any doubt. It doesn't need to add more because there are no parameters to explain.

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 tool returns a PM operating guide, using a specific verb ('returns') and a defined resource. It distinguishes itself from sibling tools by positioning it as the foundational 'house rules' to load before using other tools, which is unique among the listed operations.

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 'Call it FIRST, before planning or prioritising' and explains that other tools assume these rules. This gives unambiguous when-to-use guidance, even if it doesn't name alternatives. The instruction is actionable and context-rich.

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