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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description is consistent with both. Beyond that, it discloses three meaningful behavioral traits: it never invokes a client Gmail connector, never returns raw mail bodies, and fails soft with mailbox_reconciliation_status instead of a bare 502. The soft-failure detail is especially valuable because it tells the agent what failure output to expect and how to react.

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?

Three information-dense sentences with no filler: the first establishes purpose and architectural lineage, the second gives routing guidance, and the third lists behavioral guarantees. Each sentence earns its place, though it is slightly long relative to the tool's simplicity and could arguably fold the review_queue reference into fewer words.

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?

The output schema exists, so return-value explanation is unnecessary. The description covers purpose, sibling relationships, when-to-use, architectural behavior, and failure semantics — most of what an agent needs. The one notable gap is parameter meaning (tenant_id), which is not explained anywhere and reduces completeness for a tool that otherwise has strong annotation and output-schema support.

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?

With 0% schema description coverage, the description carries the full burden of explaining parameters, and it explains neither limit nor tenant_id. The schema provides only type constraints (integer with min/max/default, bare string), so an agent cannot know what tenant_id scopes or what limit counts. The 'mail-signal status' context hints at tenant scoping but never states it, leaving a real semantic gap.

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?

The description opens with a specific verb+resource: 'Read Talent Scout mail-signal status' and anchors it to a concrete architectural path ('the same server-side Gmail reconciliation path used by review_queue'). It distinguishes itself from the local BYOC scout.mail_signals alternative and from the sibling review_queue by naming both, so an agent can route correctly without opening the 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?

The description states the triggers and exclusions explicitly: it is the reliable StackFast replacement for local BYOC scout.mail_signals specifically 'when the cleverq.net/local tunnel is down.' It names the alternative tool/path and the condition that selects this one, while its 'never calls a client Gmail connector' statement clarifies when this tool is the wrong choice (when client-side access is desired).

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