Get seat availability

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the agent knows it's a safe, non-mutating read. The description adds value by disclosing that the provider returns an explicit unsupported status and never fabricates inventory, which is a critical behavioral detail not covered by annotations. This provides meaningful context beyond the structured fields.

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 with no filler. The key scope ('Use only to check...') is front-loaded, followed by a single behavioral note. Every word earns its place, and the structure is immediately scannable.

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-only check with an output schema (present but not shown), the description covers the core purpose, the main behavioral nuance (unsupported status), and safety via annotations. It does not describe error conditions or validate input requirements, but given the output schema exists and the tool's simplicity, what is provided is adequate.

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 50%: fromStationId and toStationId have descriptions ('Canonical ID returned by search_stations.'), while trainId and date have none. The description mentions 'exact train and station pair' but does not elaborate on how to obtain trainId or the date format, nor does it reference train identifiers from any sibling tool. Since coverage is low (<80%), the description should compensate but does not, leaving two parameters poorly documented.

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 opens with 'Use only to check whether the configured provider exposes seat inventory for an exact train and station pair', which names the verb (check), the resource (seat inventory), and the precise scope (exact train and station pair). This clearly separates it from sibling tools like get_train_details or search_journeys without ambiguity.

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 'Use only' explicitly restricts the tool to this specific check, and the description states that the default provider may return an unsupported status. However, it does not name alternative tools for broader journey planning or explicitly state when NOT to use it, though the restriction is implicit. This is clear context but lacks named alternatives.

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