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

With no annotations provided, the description carries the full burden of behavioral disclosure. It adds 'FREE' (a cost/disclosure) and 'which key scope unlocks it' (an authorization/access trait), which go beyond a bare 'list buildings' statement. It does not mention side effects or cleanup, but for a read-only directory listing, this is sufficient. The description enriches the agent's understanding of access and cost without conflicting with any annotations.

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 a single, compact sentence that front-loads the most important information ('FREE' and 'campus directory') and packs in every relevant detail: URL, tools, prices, free tier, key scope, and the 'Start here' usage cue. There is zero redundancy or fluff; every word earns its place.

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 0-parameter tool with no output schema, the description fully covers what the agent needs to know: it lists every AIS MCP building with its URL, available tools, pricing, free tier, and required key scope. It also gives a strong usage hint ('Start here'). There is no missing information that would prevent correct invocation or interpretation.

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?

This tool has 0 parameters, and the schema coverage is effectively 100% (since there is nothing to document). Per the calibration guidelines, a baseline of 4 applies. The description does not need to add parameter meaning because there are none; it instead focuses on the output content, which is appropriate.

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 verb ('list') and the resource ('every AIS MCP building'), and then enumerates the exact content: URL, tools, prices, free tier, and key scope. It positions itself as 'The campus directory,' which immediately distinguishes it from the sibling tools about_aislabs and how_to_pay. The agent can confidently know what this tool returns.

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?

'Start here' gives explicit guidance to use this as the entry point, which implies it should be called before about_aislabs or how_to_pay when the agent needs an overview. However, it does not explicitly name the alternatives or state when not to use it. The guidance is clear for the primary use case but lacks explicit exclusion criteria for the siblings.

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