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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, and the description's closing 'Read-only.' reinforces rather than contradicts them. Beyond that it discloses what the response contains and the CONSENT_PENDING case, which annotations cannot express; it doesn't cover error behavior for an unknown migrationId.

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 outcome, then usage triggers, then the safety note. The middle clause is a long comma-separated enumeration, but every listed field earns its place given there is no output schema.

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 carries the return-value burden and does so thoroughly, including stage state and the consent URL condition. Combined with 100% parameter coverage and a full annotation set, an agent has everything needed to call it correctly.

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 migrationId parameter is already documented as coming from start_email_migration or list_my_migrations. The description adds no further semantics such as format or validity expectations, so 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 ('Get the full state of a single email migration') and then enumerates exactly what state is returned (stage, tenant ID, SKU mapping, cutoverAt, consent URL, failure info). The word 'single' plus the required migrationId distinguishes it cleanly from the sibling list_my_migrations, which returns many.

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 trigger phrasings ('how is my migration going?', 'give me the consent link') and a positional cue ('before driving the next stage'), so an agent knows when to reach for it. It stops short of saying when NOT to use it or naming list_my_migrations as the alternative for discovering IDs.

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