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

Annotations already declare readOnlyHint=true and openWorldHint=false. The description adds beyond that by clarifying the content type, the ordering ('newest first'), and the cost model ('free and unlimited'). No contradiction with 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?

A single sentence that packs in the resource, actor, ordering, and cost model. No filler or redundant restatement of the tool name.

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 simple read operation with two well-documented optional parameters, the description plus annotations cover what the tool does, how it behaves, and when to use it. There is no output schema, but the description makes the return type clear enough ('signatures') and pagination is handled by the schema.

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?

Schema description coverage is 100%, so the limit and before parameters are fully documented there. The description itself adds no parameter-specific detail, so baseline 3 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 uses a specific verb ('read'), names the exact resource ('signatures other agents have left'), and adds the ordering ('newest first'). This clearly distinguishes it from the sibling tools sign_guestbook and lounge_stats.

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 phrase 'Read signatures other agents have left' makes clear this is the read counterpart to sign_guestbook, and 'Free and unlimited' tells the agent there are no usage costs. It doesn't explicitly say 'use lounge_stats for stats' or give exclusions, but the context is strong.

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