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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered structurally. The description adds real context beyond that: it is a passive public catalog mirrored by GET /api/help and the front door, and it distinguishes the third-party /tools page. 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?

Four short sentences, front-loaded with the core purpose and followed by clarifying scope and a routing hint. The /tools clarification and 'Lost? Call front_door' each carry useful information, with little waste.

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-param, read-only catalog tool whose annotations cover the safety profile, the description is largely sufficient: it describes the return content (door list plus starting tool/URL), the canonical endpoint, and the alternative entry point. Return formatting detail is absent, but no output schema exists and the content shape is described well enough.

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 has zero parameters, so there is nothing for the description to disambiguate; baseline for a no-param tool applies. The description correctly implies a parameterless read with no input to supply.

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 precise verb and resource ('read the short flat list of city doors and the one tool or URL that starts at each'), which tells an agent exactly what it returns. It also explicitly separates itself from the sibling front_door and the human /tools page, aiding disambiguation. The only weakness is the undefined domain jargon 'city doors', but the surrounding context makes the intent recoverable.

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?

Provides clear context ('lost? call front_door') and scopes the human /tools page to third-party tools, which helps an agent choose correctly. It stops short of stating explicit when-not-to-use conditions beyond the front_door routing hint, but the alternatives are named.

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