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

Beyond the annotations (readOnlyHint, idempotentHint), the description discloses important runtime behavior: unknown/unpublished IDs return { listing: null, notFound: true } without throwing, purposely to avoid leaking existence. It also notes catalog coverage and that IDs are not guessable, which adds significant context beyond the structured 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 compact (three sentences) and front-loaded with the core purpose. Every sentence adds value: the first states the main function, the second gives prerequisite and sequence, the third explains edge-case behavior and scope. No wasted words.

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?

Given the tool's simplicity (one parameter), the rich schema and annotations, and the presence of an output schema, the description is complete. It covers prerequisites, manual fallback (sourceUrl), geographic scope, and not-found behavior. Nothing important 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?

The input schema already provides comprehensive parameter semantics with 100% coverage: it explains listingId is from search_properties, not guessable, and the trailing segment of sourceUrl. The description repeats this guidance but adds no new parameter-level information beyond what the schema already documents, so the baseline of 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 clearly states the tool fetches full public details for one AVnester listing by listingId. It uses a specific verb ('Fetch') and resource ('AVnester listing'), and distinguishes itself from siblings by being the follow-up to search_properties for a single listing.

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 description gives explicit usage context: get listingId from search_properties first, and use when the user references a specific listing. It also notes catalog coverage (Coimbatore and Chennai). However, it does not explicitly name alternatives for other use cases (e.g., compare_properties for multiple listings), so it lacks a full 'when-not or alternative' statement.

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