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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds real context beyond that: what the sheet contains, that booking/payment and seat maps are deliberately excluded, and that a Checkin hand-off link is involved. It stops short of describing pagination or latency, but the safety-critical surface is well covered.

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?

Front-loaded with the resource and its contents, then usage, then required/optional params. Every sentence carries information, though the middle sentence is dense enough that a reader must parse several clauses to extract the routing rule.

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, return values need not be explained, and the description still covers contents, required/optional inputs, and scope exclusions. It is nearly complete for invocation; the only omission is any mention of the booking_deeplink parameter, which the schema carries on its own.

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 100%, so the baseline is 3, but the description adds meaning the schema does not: trip_ref must be 'the opaque tripRef from the prior search_buses card, matched exactly,' and it frames summary and booking_url by their origin on the card. It omits booking_deeplink entirely, though the schema documents it.

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 and resource ('Shows the Bus Details sheet for one trip from search_buses') and enumerates the payload it surfaces: amenities, pickup/dropping points, cancellation slabs, rating, CTA. It explicitly positions itself relative to search_buses, so an agent can distinguish it from the search sibling without opening either schema.

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?

Names the trigger conditions ('source for amenities, boarding/dropping points, cancellation policy, or details for a specific bus, including a tap on a bus card in the widget') and rules out an unnecessary alternative call ('The tripRef from the card is enough, without a new search_buses call'). It also bounds scope with 'No seat map or payment in chat — booking continues on Paytm Checkin'.

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