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

Annotations declare readOnlyHint=false, openWorldHint=true and destructiveHint=false, and the description adds genuinely non-redundant behavior: it returns a session ID for an asynchronous poll cycle, names the upstream fare providers, and explains that missing route/date yields a clarifying question rather than an error. No contradiction with 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?

Four sentences, front-loaded with the action and scope, then the async contract and the missing-input fallback. Dense with no filler, though the provider list is marketing-adjacent detail that an agent does not strictly need to select the tool.

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?

An output schema exists so return fields need not be explained, and the description still covers the key async handoff to poll_flight_results plus the missing-input behavior. Given 8 mostly-optional parameters and a mutation-style session creation, it is complete enough; only the absence of guidance on optional inputs like cabin/adults in prose keeps it from a 5.

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 100%, so every parameter (origin, destination, dates, cabin, adults, language, queryText) is already documented with format patterns and defaults in the schema. The description restates the IATA 3-letter convention and one-way/return semantics but adds no format or constraint detail beyond the structured fields, so the baseline 3 applies.

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 ('Starts a live flight search for a route and date, one-way or return') and explicitly distinguishes itself from the sibling that completes the job ('poll_flight_results returns the results'). An agent can separate it from search_hotels_live and the poll_* tools without opening a 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?

Gives clear routing to the follow-up tool (poll_flight_results) and describes the degenerate case where required inputs are absent ('the result is a question for the user instead of a search'). It does not state exclusions such as when a cached/batch search would be preferable, so it falls short of a full when/when-not treatment.

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