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

Annotations already supply the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=true). The description adds that this creates a persistent recurring-monitoring entry, which is real context, but says nothing about duplicate handling if the tail is already tracked, permission requirements, or whether the entry can be removed.

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, zero filler, with the purpose of the tool front-loaded before the parameter requirements. Every clause earns its place.

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 values need not be explained, and the annotations cover the write/safety profile. However, for a tool that mutates a watchlist, the description omits duplicate-tracking behavior and the relationship between the optional registration and the required aircraft_info, leaving gaps.

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 only 33%, so the schema does not carry the load. The description names make_model_id and aircraft_info.year as required and explains that registration identifies the tail, but does not say where make_model_id comes from (e.g., search_make_models) or how registration relates to the required aircraft_info.

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?

Specific verb+resource: add a tail to a portfolio watchlist, with stated purpose (recurring valuation snapshots, change monitoring). This distinguishes it from one-off valuation siblings like value_aircraft and from read paths like list_tracked_aircraft.

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 'recurring valuation snapshots and change monitoring' implies when this is appropriate versus a single valuation, but no alternative is named and no condition or prerequisite is stated. Usage is inferable rather than explicit.

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