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 trailing "Read-only" sentence is largely redundant. The one genuinely additive behavioral fact is that results include every state rather than only active or only completed ones. Nothing is said about ordering, truncation, or cursor/paging behavior beyond the limit cap that the schema already documents.

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 core purpose and state scope come first, followed by usage triggers, so it is well front-loaded. The closing "Read-only." fragment is dead weight given the annotations, keeping it just short of a 5.

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 no output schema, the description does enough by listing the state values an agent can expect and by flagging that migrationId is retrievable from results. It stops short of describing the returned fields or what happens when there are more migrations than the limit, which an agent composing a follow-up call would want.

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% and the single limit parameter already carries its default (10) and maximum (25) in the schema. The description adds no meaning about how limit interacts with the listed states, so it neither helps nor misleads — 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 ("List the customer's email migrations") plus the scope "across all states" with those states enumerated. This distinguishes it from get_migration_status, which is clearly keyed to a single migration, and from the other list_my_* siblings by naming the resource as email migrations.

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 concrete triggers, including three verbatim user phrasings and the secondary purpose of resolving a migrationId for a follow-up action like cancel. It never explicitly names get_migration_status as the alternative when the ID is already known, so the routing signal is clear but not fully closed.

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