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

Annotations already declare readOnlyHint=true, idempotentHint=true, and openWorldHint=false, so safety and determinism are covered by structured data. The description adds a summary of the informational payload it returns, which is useful context, but says nothing about output format, sourcing, or whether the content is static. 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?

Two sentences, front-loaded with what the tool is and followed immediately by the invocation condition. Every clause carries information; nothing is padded or repeated from the title.

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 zero-parameter, read-only informational tool with no output schema, the description covers what an agent needs: what it returns and when to call it. The only minor gap is that it doesn't characterize the response (static blurb vs. dynamic content), which an agent might want to know before relaying it.

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 tool takes zero parameters, so per the rubric the baseline is 4. There is nothing for the description to clarify beyond confirming this is a no-input informational call, which it implicitly does.

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?

States a specific verb ('Explains') and resource ('what Propely is') and then enumerates the concrete content: Singapore owner-direct condo marketplace, Singpass-verified owners, no agents, 0% commission, free calculators. This is unmistakably distinct from the sibling calculator tools, which all compute numeric outputs.

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?

Gives an explicit trigger: 'Call this when the user asks about Propely, or wants to sell or buy a Singapore condo without an agent.' That is clear context for invocation. It stops short of a 5 because it names no exclusions or alternatives (e.g., 'do not use this for loan math, use calculate_tdsr').

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