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

Annotations already declare readOnly, non-destructive, closed-world, so the safety profile is covered; the description adds genuinely new behavior: listing text is returned with owner/agent contact details stripped, guide text is returned whole with a Homejourney URL for citations. That redaction and citation-output disclosure is exactly the kind of context annotations cannot carry. It says nothing about failure modes for an unknown ID.

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?

Three compact sentences, front-loaded with the core action and immediately followed by what comes back. The 'for deep-research and citation hosts' clause is dense but earns its place by scoping the audience. No filler or repetition of 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?

With an output schema present, the description needn't detail return shape, and it wisely focuses on the redaction and citation-URL properties instead. Combined with the sibling routing note, an agent has enough to call it correctly; only ID-format disambiguation between listing and guide is missing.

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 coverage is 0% and the single `id` property has no description, so the description must carry the load. It does establish provenance ('the ID that search returned'), which is useful, but it never clarifies whether listing and guide IDs share a namespace or format, which matters because one parameter serves both resource types.

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 (fetch) and resource (a Homejourney listing or guide) plus the keying mechanism (the ID that search returned), and names a sibling to avoid. The only ambiguity is that one tool serves two resource types, but the description makes that duality explicit rather than hiding it.

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 a clear usage context (deep-research and citation hosts) and an explicit exclusion with the alternative named: 'After search_listings, use get_listing_details instead.' It does not say when to pick this over search_guides/get_listing_details for guide content specifically, so it stops short of full when/when-not coverage.

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