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

The description goes well beyond the readOnlyHint annotation by explaining what a bare call returns (a 'Character-voiced director's note' with specific actions) and that it hands the agent MOVES rather than a script, even warning against verbatim relay. It also describes the step progression's output format, including 'a concrete action and a validation criterion,' giving full behavioral transparency.

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 dense but well-structured: first sentence establishes primary purpose, second details the bare-call behavior, third explains the step parameter. Every sentence carries essential information, and the opening is front-loaded with 'The welcome — call this FIRST.' However, the extended metaphorical language (e.g., 'blodge', 'keyless act') adds some length and potential ambiguity, so it earns a 4 rather than 5.

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?

With no output schema, the description compensates by describing the expected return for bare calls (director's note, MOVES) and for step calls (concrete action and validation criterion). Combined with the schema's step enumeration and the readOnlyHint annotation, the tool is fully contextualized for an agent. Minor gaps like error handling or invalid-step behavior prevent a 5.

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 provides 100% coverage of the 'step' parameter with a detailed description of each step's meaning and progression. The description adds the crucial audience distinction ('ONLY for the OTHER audience') and the overall build-ladder context, which enhances understanding beyond the schema. This extra context justifies moving above the baseline of 3.

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 'The welcome — call this FIRST when a person arrives or asks what this place is,' clearly stating the tool's core purpose as an orientation entry point. It also distinguishes itself from siblings by explicitly being first and by describing two distinct audiences (human arrival vs agent build ladder), making its function unique among the listed siblings.

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 provides explicit when-to-use guidance: 'call this FIRST when a person arrives or asks what this place is.' For the step parameter, it clearly says 'Pass step=1..6 ONLY for the OTHER audience — an agent orienting itself to build substrate capacity,' which clarifies exactly when to use the non-bare invocation and differentiates from the welcome scenario.

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